Remove FunctionType (#2510)

Function signatures were previously redundantly stored on Function
objects as well as on FunctionType objects. These two signature
representations had to always be kept in sync, which was error-prone
and needlessly complex. This PR takes advantage of the new ability of
Type to represent multiple value types by consolidating function
signatures as a pair of Types (params and results) stored on the
Function object.

Since there are no longer module-global named function types,
significant changes had to be made to the printing and emitting of
function types, as well as their parsing and manipulation in various
passes.

The C and JS APIs and their tests also had to be updated to remove
named function types.

1 files changed, 2 insertions, 9 deletions

diff --git a/src/ir/hashed.h b/src/ir/hashed.h
index a3d285cf5..9e9717cda 100644
--- a/src/ir/hashed.h
+++ b/src/ir/hashed.h
@@ -82,18 +82,11 @@ struct FunctionHasher : public WalkerPass<PostWalker<FunctionHasher>> {
 
   static HashType hashFunction(Function* func) {
     HashType ret = 0;
-    ret = rehash(ret, (HashType)func->getNumParams());
-    for (auto type : func->params) {
-      ret = rehash(ret, (HashType)type);
-    }
-    ret = rehash(ret, (HashType)func->getNumVars());
+    ret = rehash(ret, (HashType)func->sig.params);
+    ret = rehash(ret, (HashType)func->sig.results);
     for (auto type : func->vars) {
       ret = rehash(ret, (HashType)type);
     }
-    ret = rehash(ret, (HashType)func->result);
-    ret = rehash(ret,
-                 HashType(func->type.is() ? std::hash<wasm::Name>{}(func->type)
-                                          : HashType(0)));
     ret = rehash(ret, (HashType)ExpressionAnalyzer::hash(func->body));
     return ret;
   }