Remove the GCNNLocals feature (#5080)

Now that the WasmGC spec has settled on a way of validating non-nullable locals,
we no longer need this experimental feature that allowed nonstandard uses of
non-nullable locals.

1 files changed, 2 insertions, 10 deletions

diff --git a/src/passes/OptimizeInstructions.cpp b/src/passes/OptimizeInstructions.cpp
index f15bac23d..0b787105e 100644
--- a/src/passes/OptimizeInstructions.cpp
+++ b/src/passes/OptimizeInstructions.cpp
@@ -1155,17 +1155,9 @@ struct OptimizeInstructions
 
   void visitLocalSet(LocalSet* curr) {
     // Interactions between local.set/tee and ref.as_non_null can be optimized
-    // in some cases, by removing or moving the ref.as_non_null operation. In
-    // all cases, we only do this when we do *not* allow non-nullable locals. If
-    // we do allow such locals, then (1) this local might be non-nullable, so we
-    // can't remove or move a ref.as_non_null flowing into a local.set/tee, and
-    // (2) even if the local were nullable, if we change things we might prevent
-    // the LocalSubtyping pass from turning it into a non-nullable local later.
-    // Note that we must also check if this local is nullable regardless, as a
-    // parameter might be non-nullable even if nullable locals are disallowed
-    // (as that just affects vars, and not params).
+    // in some cases, by removing or moving the ref.as_non_null operation.
     if (auto* as = curr->value->dynCast<RefAs>()) {
-      if (as->op == RefAsNonNull && !getModule()->features.hasGCNNLocals() &&
+      if (as->op == RefAsNonNull &&
           getFunction()->getLocalType(curr->index).isNullable()) {
         //   (local.tee (ref.as_non_null ..))
         // =>