[GC] Add struct.set (#3430)

Mostly straightforward after struct.get.

This renames the value field in struct.get to ref. I think this makes
more sense because struct.set has both a reference to a thing, and a
value to set onto that thing. So calling the former ref seems more
consistent, giving us ref, value. This mirrors load/store for example
where we use ptr, value, and ref is playing the role of ptr here
basically.

1 files changed, 6 insertions, 2 deletions

diff --git a/src/wasm.h b/src/wasm.h
index cc390573d..c1b5b4bdf 100644
--- a/src/wasm.h
+++ b/src/wasm.h
@@ -1353,7 +1353,7 @@ public:
   StructGet(MixedArena& allocator) {}
 
   Index index;
-  Expression* value;
+  Expression* ref;
   // Packed fields have a sign.
   bool signed_ = false;
 
@@ -1364,7 +1364,11 @@ class StructSet : public SpecificExpression<Expression::StructSetId> {
 public:
   StructSet(MixedArena& allocator) {}
 
-  void finalize() { WASM_UNREACHABLE("TODO (gc): struct.set"); }
+  Index index;
+  Expression* ref;
+  Expression* value;
+
+  void finalize();
 };
 
 class ArrayNew : public SpecificExpression<Expression::ArrayNewId> {