Replace `RefIs` with `RefIsNull` (#5401)

* Replace `RefIs` with `RefIsNull`

The other `ref.is*` instructions are deprecated and expressible in terms of
`ref.test`. Update binary and text parsing to parse those instructions as
`RefTest` expressions. Also update the printing and emitting of `RefTest`
expressions to emit the legacy instructions for now to minimize test changes and
make this a mostly non-functional change. Since `ref.is_null` is the only
`RefIs` instruction left, remove the `RefIsOp` field and rename the expression
class to `RefIsNull`.

The few test changes are due to the fact that `ref.is*` instructions are now
subject to `ref.test` validation, and in particular it is no longer valid to
perform a `ref.is_func` on a value outside of the `func` type hierarchy.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/wasm2js.h b/src/wasm2js.h
index 25931db85..eddb26866 100644
--- a/src/wasm2js.h
+++ b/src/wasm2js.h
@@ -2206,7 +2206,7 @@ Ref Wasm2JSBuilder::processFunctionBody(Module* m,
       unimplemented(curr);
       WASM_UNREACHABLE("unimp");
     }
-    Ref visitRefIs(RefIs* curr) {
+    Ref visitRefIsNull(RefIsNull* curr) {
       unimplemented(curr);
       WASM_UNREACHABLE("unimp");
     }