Remove unused `isNominal` field on HeapTypeInfo (#4465)

This field was originally added with the goal of allowing types from multiple
type systems to coexist by determining the type system on a per-type level
rather than globally. This goal was never fully achieved and the `isNominal`
field is not used outside of tests. Now that we are working on implementing the
hybrid isorecursive system, it does not look like having types from multiple
systems coexist will be useful in the near term, so clean up this tech debt.

1 files changed, 1 insertions, 3 deletions

diff --git a/src/wasm/wasm-binary.cpp b/src/wasm/wasm-binary.cpp
index 36cb0fd1a..b20269f9b 100644
--- a/src/wasm/wasm-binary.cpp
+++ b/src/wasm/wasm-binary.cpp
@@ -224,7 +224,7 @@ void WasmBinaryWriter::writeTypes() {
   o << U32LEB(indexedTypes.types.size());
   for (Index i = 0; i < indexedTypes.types.size(); ++i) {
     auto type = indexedTypes.types[i];
-    bool nominal = type.isNominal() || getTypeSystem() == TypeSystem::Nominal;
+    bool nominal = getTypeSystem() == TypeSystem::Nominal;
     BYN_TRACE("write " << type << std::endl);
     if (type.isSignature()) {
       o << S32LEB(nominal ? BinaryConsts::EncodedType::FuncExtending
@@ -1962,8 +1962,6 @@ void WasmBinaryBuilder::readTypes() {
     if (form == BinaryConsts::EncodedType::FuncExtending ||
         form == BinaryConsts::EncodedType::StructExtending ||
         form == BinaryConsts::EncodedType::ArrayExtending) {
-      // TODO: Let the new nominal types coexist with equirecursive types
-      // builder[i].setNominal();
       auto superIndex = getS64LEB(); // TODO: Actually s33
       if (superIndex >= 0) {
         if (size_t(superIndex) >= numTypes) {