Define the implicit func type before the function (#400)

When a function is defined without an explicit type, it will first
search the already defined (implicitly or otherwise) func types. If one
is found, it will use it. Otherwise it will define its own and use that.

The code previously would define this new type after the function, which
works but doesn't roundtrip properly because it ends up defining the
same func type twice.

4 files changed, 96 insertions, 74 deletions

diff --git a/src/ast-parser.y b/src/ast-parser.y
index 5f0498dd..ff788670 100644
--- a/src/ast-parser.y
+++ b/src/ast-parser.y
@@ -1171,8 +1171,10 @@ module_fields :
   | module_fields func {
       $$ = $1;
       ModuleField* field;
+      // Append the implicit func declaration first so it occurs before the
+      // func definition when serialized out to the text format.
+      append_implicit_func_declaration(&@2, $$, &$2->func->decl);
       APPEND_FIELD_TO_LIST($$, field, Func, func, @2, $2->func.release());
-      append_implicit_func_declaration(&@2, $$, &field->func->decl);
       APPEND_ITEM_TO_VECTOR($$, funcs, field->func);
       INSERT_BINDING($$, func, funcs, @2, field->func->name);
       APPEND_INLINE_EXPORT($$, Func, @2, $2, $$->funcs.size() - 1);
diff --git a/src/prebuilt/ast-parser-gen.cc b/src/prebuilt/ast-parser-gen.cc
index 32c4c754..1cc209b7 100644
--- a/src/prebuilt/ast-parser-gen.cc
+++ b/src/prebuilt/ast-parser-gen.cc
@@ -1,8 +1,8 @@
-/* A Bison parser, made by GNU Bison 3.0.2.  */
+/* A Bison parser, made by GNU Bison 3.0.4.  */
 
 /* Bison implementation for Yacc-like parsers in C
 
-   Copyright (C) 1984, 1989-1990, 2000-2013 Free Software Foundation, Inc.
+   Copyright (C) 1984, 1989-1990, 2000-2015 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -44,7 +44,7 @@
 #define YYBISON 1
 
 /* Bison version.  */
-#define YYBISON_VERSION "3.0.2"
+#define YYBISON_VERSION "3.0.4"
 
 /* Skeleton name.  */
 #define YYSKELETON_NAME "yacc.c"
@@ -699,10 +699,10 @@ static const yytype_uint16 yyrline[] =
      945,   953,   966,   974,   982,   988,   994,  1002,  1007,  1015,
     1023,  1029,  1035,  1044,  1052,  1057,  1062,  1067,  1074,  1081,
     1085,  1088,  1100,  1105,  1114,  1118,  1121,  1128,  1137,  1154,
-    1171,  1181,  1187,  1193,  1199,  1232,  1242,  1262,  1273,  1301,
-    1306,  1314,  1324,  1334,  1340,  1346,  1352,  1358,  1364,  1369,
-    1374,  1380,  1389,  1394,  1395,  1400,  1409,  1410,  1417,  1429,
-    1430,  1437,  1503
+    1171,  1183,  1189,  1195,  1201,  1234,  1244,  1264,  1275,  1303,
+    1308,  1316,  1326,  1336,  1342,  1348,  1354,  1360,  1366,  1371,
+    1376,  1382,  1391,  1396,  1397,  1402,  1411,  1412,  1419,  1431,
+    1432,  1439,  1505
 };
 #endif
 
@@ -3677,51 +3677,53 @@ yyreduce:
     {
       (yyval.module) = (yyvsp[-1].module);
       ModuleField* field;
+      // Append the implicit func declaration first so it occurs before the
+      // func definition when serialized out to the text format.
+      append_implicit_func_declaration(&(yylsp[0]), (yyval.module), &(yyvsp[0].exported_func)->func->decl);
       APPEND_FIELD_TO_LIST((yyval.module), field, Func, func, (yylsp[0]), (yyvsp[0].exported_func)->func.release());
-      append_implicit_func_declaration(&(yylsp[0]), (yyval.module), &field->func->decl);
       APPEND_ITEM_TO_VECTOR((yyval.module), funcs, field->func);
       INSERT_BINDING((yyval.module), func, funcs, (yylsp[0]), field->func->name);
       APPEND_INLINE_EXPORT((yyval.module), Func, (yylsp[0]), (yyvsp[0].exported_func), (yyval.module)->funcs.size() - 1);
       delete (yyvsp[0].exported_func);
     }
-#line 3688 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3690 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 141:
-#line 1181 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1183 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.module) = (yyvsp[-1].module);
       ModuleField* field;
       APPEND_FIELD_TO_LIST((yyval.module), field, ElemSegment, elem_segment, (yylsp[0]), (yyvsp[0].elem_segment));
       APPEND_ITEM_TO_VECTOR((yyval.module), elem_segments, field->elem_segment);
     }
-#line 3699 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3701 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 142:
-#line 1187 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1189 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.module) = (yyvsp[-1].module);
       ModuleField* field;
       APPEND_FIELD_TO_LIST((yyval.module), field, DataSegment, data_segment, (yylsp[0]), (yyvsp[0].data_segment));
       APPEND_ITEM_TO_VECTOR((yyval.module), data_segments, field->data_segment);
     }
-#line 3710 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3712 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 143:
-#line 1193 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1195 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.module) = (yyvsp[-1].module);
       ModuleField* field;
       APPEND_FIELD_TO_LIST((yyval.module), field, Start, start, (yylsp[0]), (yyvsp[0].var));
       (yyval.module)->start = &field->start;
     }
-#line 3721 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3723 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 144:
-#line 1199 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1201 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.module) = (yyvsp[-1].module);
       ModuleField* field;
@@ -3755,11 +3757,11 @@ yyreduce:
       }
       APPEND_ITEM_TO_VECTOR((yyval.module), imports, field->import);
     }
-#line 3759 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3761 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 145:
-#line 1232 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1234 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.module) = (yyvsp[-1].module);
       ModuleField* field;
@@ -3767,11 +3769,11 @@ yyreduce:
       APPEND_ITEM_TO_VECTOR((yyval.module), exports, field->export_);
       INSERT_BINDING((yyval.module), export, exports, (yylsp[0]), field->export_->name);
     }
-#line 3771 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3773 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 146:
-#line 1242 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1244 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.raw_module) = new RawModule();
       (yyval.raw_module)->type = RawModuleType::Text;
@@ -3792,11 +3794,11 @@ yyreduce:
         }
       }
     }
-#line 3796 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3798 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 147:
-#line 1262 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1264 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.raw_module) = new RawModule();
       (yyval.raw_module)->type = RawModuleType::Binary;
@@ -3805,11 +3807,11 @@ yyreduce:
       dup_text_list(&(yyvsp[-1].text_list), &(yyval.raw_module)->binary.data, &(yyval.raw_module)->binary.size);
       destroy_text_list(&(yyvsp[-1].text_list));
     }
-#line 3809 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3811 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 148:
-#line 1273 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1275 "src/ast-parser.y" /* yacc.c:1646  */
     {
       if ((yyvsp[0].raw_module)->type == RawModuleType::Text) {
         (yyval.module) = (yyvsp[0].raw_module)->text;
@@ -3833,31 +3835,31 @@ yyreduce:
       }
       delete (yyvsp[0].raw_module);
     }
-#line 3837 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3839 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 149:
-#line 1301 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1303 "src/ast-parser.y" /* yacc.c:1646  */
     {
       WABT_ZERO_MEMORY((yyval.var));
       (yyval.var).type = VarType::Index;
       (yyval.var).index = INVALID_VAR_INDEX;
     }
-#line 3847 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3849 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 150:
-#line 1306 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1308 "src/ast-parser.y" /* yacc.c:1646  */
     {
       WABT_ZERO_MEMORY((yyval.var));
       (yyval.var).type = VarType::Name;
       DUPTEXT((yyval.var).name, (yyvsp[0].text));
     }
-#line 3857 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3859 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 151:
-#line 1314 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1316 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.action) = new Action();
       (yyval.action)->loc = (yylsp[-4]);
@@ -3868,11 +3870,11 @@ yyreduce:
       (yyval.action)->invoke->args = std::move(*(yyvsp[-1].consts));
       delete (yyvsp[-1].consts);
     }
-#line 3872 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3874 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 152:
-#line 1324 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1326 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.action) = new Action();
       (yyval.action)->loc = (yylsp[-3]);
@@ -3880,128 +3882,128 @@ yyreduce:
       (yyval.action)->type = ActionType::Get;
       (yyval.action)->name = (yyvsp[-1].text);
     }
-#line 3884 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3886 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 153:
-#line 1334 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1336 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.command) = new Command();
       (yyval.command)->type = CommandType::AssertMalformed;
       (yyval.command)->assert_malformed.module = (yyvsp[-2].raw_module);
       (yyval.command)->assert_malformed.text = (yyvsp[-1].text);
     }
-#line 3895 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3897 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 154:
-#line 1340 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1342 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.command) = new Command();
       (yyval.command)->type = CommandType::AssertInvalid;
       (yyval.command)->assert_invalid.module = (yyvsp[-2].raw_module);
       (yyval.command)->assert_invalid.text = (yyvsp[-1].text);
     }
-#line 3906 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3908 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 155:
-#line 1346 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1348 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.command) = new Command();
       (yyval.command)->type = CommandType::AssertUnlinkable;
       (yyval.command)->assert_unlinkable.module = (yyvsp[-2].raw_module);
       (yyval.command)->assert_unlinkable.text = (yyvsp[-1].text);
     }
-#line 3917 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3919 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 156:
-#line 1352 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1354 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.command) = new Command();
       (yyval.command)->type = CommandType::AssertUninstantiable;
       (yyval.command)->assert_uninstantiable.module = (yyvsp[-2].raw_module);
       (yyval.command)->assert_uninstantiable.text = (yyvsp[-1].text);
     }
-#line 3928 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3930 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 157:
-#line 1358 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1360 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.command) = new Command();
       (yyval.command)->type = CommandType::AssertReturn;
       (yyval.command)->assert_return.action = (yyvsp[-2].action);
       (yyval.command)->assert_return.expected = (yyvsp[-1].consts);
     }
-#line 3939 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3941 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 158:
-#line 1364 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1366 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.command) = new Command();
       (yyval.command)->type = CommandType::AssertReturnCanonicalNan;
       (yyval.command)->assert_return_canonical_nan.action = (yyvsp[-1].action);
     }
-#line 3949 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3951 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 159:
-#line 1369 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1371 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.command) = new Command();
       (yyval.command)->type = CommandType::AssertReturnArithmeticNan;
       (yyval.command)->assert_return_arithmetic_nan.action = (yyvsp[-1].action);
     }
-#line 3959 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3961 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 160:
-#line 1374 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1376 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.command) = new Command();
       (yyval.command)->type = CommandType::AssertTrap;
       (yyval.command)->assert_trap.action = (yyvsp[-2].action);
       (yyval.command)->assert_trap.text = (yyvsp[-1].text);
     }
-#line 3970 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3972 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 161:
-#line 1380 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1382 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.command) = new Command();
       (yyval.command)->type = CommandType::AssertExhaustion;
       (yyval.command)->assert_trap.action = (yyvsp[-2].action);
       (yyval.command)->assert_trap.text = (yyvsp[-1].text);
     }
-#line 3981 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3983 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 162:
-#line 1389 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1391 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.command) = new Command();
       (yyval.command)->type = CommandType::Action;
       (yyval.command)->action = (yyvsp[0].action);
     }
-#line 3991 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 3993 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 164:
-#line 1395 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1397 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.command) = new Command();
       (yyval.command)->type = CommandType::Module;
       (yyval.command)->module = (yyvsp[0].module);
     }
-#line 4001 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 4003 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 165:
-#line 1400 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1402 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.command) = new Command();
       (yyval.command)->type = CommandType::Register;
@@ -4009,26 +4011,26 @@ yyreduce:
       (yyval.command)->register_.var = (yyvsp[-1].var);
       (yyval.command)->register_.var.loc = (yylsp[-1]);
     }
-#line 4013 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 4015 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 166:
-#line 1409 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1411 "src/ast-parser.y" /* yacc.c:1646  */
     { (yyval.commands) = new CommandPtrVector(); }
-#line 4019 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 4021 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 167:
-#line 1410 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1412 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.commands) = (yyvsp[-1].commands);
       (yyval.commands)->emplace_back((yyvsp[0].command));
     }
-#line 4028 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 4030 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 168:
-#line 1417 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1419 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.const_).loc = (yylsp[-2]);
       if (WABT_FAILED(parse_const((yyvsp[-2].type), (yyvsp[-1].literal).type, (yyvsp[-1].literal).text.start,
@@ -4039,26 +4041,26 @@ yyreduce:
       }
       delete [] (yyvsp[-1].literal).text.start;
     }
-#line 4043 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 4045 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 169:
-#line 1429 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1431 "src/ast-parser.y" /* yacc.c:1646  */
     { (yyval.consts) = new ConstVector(); }
-#line 4049 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 4051 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 170:
-#line 1430 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1432 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.consts) = (yyvsp[-1].consts);
       (yyval.consts)->push_back((yyvsp[0].const_));
     }
-#line 4058 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 4060 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
   case 171:
-#line 1437 "src/ast-parser.y" /* yacc.c:1646  */
+#line 1439 "src/ast-parser.y" /* yacc.c:1646  */
     {
       (yyval.script) = new Script();
       (yyval.script)->commands = std::move(*(yyvsp[0].commands));
@@ -4120,11 +4122,11 @@ yyreduce:
       }
       parser->script = (yyval.script);
     }
-#line 4124 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 4126 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
     break;
 
 
-#line 4128 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
+#line 4130 "src/prebuilt/ast-parser-gen.cc" /* yacc.c:1646  */
       default: break;
     }
   /* User semantic actions sometimes alter yychar, and that requires
@@ -4359,7 +4361,7 @@ yyreturn:
 #endif
   return yyresult;
 }
-#line 1506 "src/ast-parser.y" /* yacc.c:1906  */
+#line 1508 "src/ast-parser.y" /* yacc.c:1906  */
 
 
 void append_expr_list(ExprList* expr_list, ExprList* expr) {
diff --git a/src/prebuilt/ast-parser-gen.hh b/src/prebuilt/ast-parser-gen.hh
index 53b5e4e3..99b19c83 100644
--- a/src/prebuilt/ast-parser-gen.hh
+++ b/src/prebuilt/ast-parser-gen.hh
@@ -1,8 +1,8 @@
-/* A Bison parser, made by GNU Bison 3.0.2.  */
+/* A Bison parser, made by GNU Bison 3.0.4.  */
 
 /* Bison interface for Yacc-like parsers in C
 
-   Copyright (C) 1984, 1989-1990, 2000-2013 Free Software Foundation, Inc.
+   Copyright (C) 1984, 1989-1990, 2000-2015 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
diff --git a/test/desugar/implicit-func-type.txt b/test/desugar/implicit-func-type.txt
new file mode 100644
index 00000000..82d7b178
--- /dev/null
+++ b/test/desugar/implicit-func-type.txt
@@ -0,0 +1,18 @@
+;;; TOOL: wast-desugar
+(module
+  ;; The implicitly defined function type should come before the function,
+  ;; otherwise the function will not "see" it and define its own.
+  (func (param i32)
+    nop)
+
+  ;; This won't define a new function type, it will reuse the one above.
+  (func (param i32)
+    nop))
+(;; STDOUT ;;;
+(module
+  (type (;0;) (func (param i32)))
+  (func (;0;) (param i32)
+    nop)
+  (func (;1;) (param i32)
+    nop))
+;;; STDOUT ;;)