[GC] RefIsNull => RefIs. (#3516)

This internal refactoring prepares us for ref.is_func/data/i31, by renaming
the node and adding an "op" field. For now that field must always be "Null"
which means it is a ref.is_null.

This adjusts the C API to match the new IR shape. The high-level JS API
is unchanged.

1 files changed, 10 insertions, 3 deletions

diff --git a/src/wasm/wasm-binary.cpp b/src/wasm/wasm-binary.cpp
index bf71d3a4d..b3f085b36 100644
--- a/src/wasm/wasm-binary.cpp
+++ b/src/wasm/wasm-binary.cpp
@@ -2865,7 +2865,7 @@ BinaryConsts::ASTNodes WasmBinaryBuilder::readExpression(Expression*& curr) {
       visitRefNull((curr = allocator.alloc<RefNull>())->cast<RefNull>());
       break;
     case BinaryConsts::RefIsNull:
-      visitRefIsNull((curr = allocator.alloc<RefIsNull>())->cast<RefIsNull>());
+      visitRefIs((curr = allocator.alloc<RefIs>())->cast<RefIs>(), code);
       break;
     case BinaryConsts::RefFunc:
       visitRefFunc((curr = allocator.alloc<RefFunc>())->cast<RefFunc>());
@@ -5528,8 +5528,15 @@ void WasmBinaryBuilder::visitRefNull(RefNull* curr) {
   curr->finalize(getHeapType());
 }
 
-void WasmBinaryBuilder::visitRefIsNull(RefIsNull* curr) {
-  BYN_TRACE("zz node: RefIsNull\n");
+void WasmBinaryBuilder::visitRefIs(RefIs* curr, uint8_t code) {
+  BYN_TRACE("zz node: RefIs\n");
+  switch (code) {
+    case BinaryConsts::RefIsNull:
+      curr->op = RefIsNull;
+      break;
+    default:
+      WASM_UNREACHABLE("invalid code for ref.is_*");
+  }
   curr->value = popNonVoidExpression();
   curr->finalize();
 }