[EH][GC] Send a non-nullable exnref from TryTable (#7013)

When EH+GC are enabled then wasm has non-nullable types, and the
sent exnref should be non-nullable. In BinaryenIR we use the non-
nullable type all the time, which we also do for function references
and other things; we lower it if GC is not enabled to a nullable type
for the binary format (see `WasmBinaryWriter::writeType`, to which
comments were added in this PR). That is, this PR makes us handle
exnref the same as those other types.

A new test verifies that behavior. Various existing tests are updated
because ReFinalize will now use the more refined type, so this is
an optimization. It is also a bugfix as in #6987 we started to emit
the refined form in the fuzzer, and this PR makes us handle it
properly in validation and ReFinalization.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/wasm/wasm-validator.cpp b/src/wasm/wasm-validator.cpp
index a86187fa7..0184e3284 100644
--- a/src/wasm/wasm-validator.cpp
+++ b/src/wasm/wasm-validator.cpp
@@ -2658,7 +2658,7 @@ void FunctionValidator::visitTryTable(TryTable* curr) {
                 "the number of catch tags and sent types do not match");
 
   const char* invalidSentTypeMsg = "invalid catch sent type information";
-  Type exnref = Type(HeapType::exn, Nullable);
+  Type exnref = Type(HeapType::exn, NonNullable);
   for (Index i = 0; i < curr->catchTags.size(); i++) {
     auto sentType = curr->sentTypes[i];
     size_t tagTypeSize;