Preserve Function HeapTypes (#3952)

When using nominal types, func.ref of two functions with identical signatures
but different HeapTypes will yield different types. To preserve these semantics,
Functions need to track their HeapTypes, not just their Signatures.

This PR replaces the Signature field in Function with a HeapType field and adds
new utility methods to make it almost as simple to update and query the function
HeapType as it was to update and query the Function Signature.

1 files changed, 2 insertions, 2 deletions

diff --git a/src/tools/spec-wrapper.h b/src/tools/spec-wrapper.h
index 32e547f1b..3a490c954 100644
--- a/src/tools/spec-wrapper.h
+++ b/src/tools/spec-wrapper.h
@@ -24,7 +24,7 @@
 
 namespace wasm {
 
-static std::string generateSpecWrapper(Module& wasm) {
+inline std::string generateSpecWrapper(Module& wasm) {
   std::string ret;
   for (auto& exp : wasm.exports) {
     auto* func = wasm.getFunctionOrNull(exp->value);
@@ -33,7 +33,7 @@ static std::string generateSpecWrapper(Module& wasm) {
     }
     ret += std::string("(invoke \"hangLimitInitializer\") (invoke \"") +
            exp->name.str + "\" ";
-    for (const auto& param : func->sig.params) {
+    for (const auto& param : func->getParams()) {
       // zeros in arguments TODO more?
       TODO_SINGLE_COMPOUND(param);
       switch (param.getBasic()) {