Add support for reference types proposal (#2451)

This adds support for the reference type proposal. This includes support
for all reference types (`anyref`, `funcref`(=`anyfunc`), and `nullref`)
and four new instructions: `ref.null`, `ref.is_null`, `ref.func`, and
new typed `select`. This also adds subtype relationship support between
reference types.

This does not include table instructions yet. This also does not include
wasm2js support.

Fixes #2444 and fixes #2447.

1 files changed, 9 insertions, 4 deletions

diff --git a/src/asmjs/asm_v_wasm.cpp b/src/asmjs/asm_v_wasm.cpp
index 3720ca079..5959db43e 100644
--- a/src/asmjs/asm_v_wasm.cpp
+++ b/src/asmjs/asm_v_wasm.cpp
@@ -53,10 +53,11 @@ AsmType wasmToAsmType(Type type) {
       return ASM_INT64;
     case v128:
       assert(false && "v128 not implemented yet");
+    case funcref:
     case anyref:
-      assert(false && "anyref is not supported by asm2wasm");
+    case nullref:
     case exnref:
-      assert(false && "exnref is not supported by asm2wasm");
+      assert(false && "reference types are not supported by asm2wasm");
     case none:
       return ASM_NONE;
     case unreachable:
@@ -77,10 +78,14 @@ char getSig(Type type) {
       return 'd';
     case v128:
       return 'V';
+    case funcref:
+      return 'F';
     case anyref:
-      return 'a';
+      return 'A';
+    case nullref:
+      return 'N';
     case exnref:
-      return 'e';
+      return 'E';
     case none:
       return 'v';
     case unreachable: