[GC] ref.as_* (#3520)

These are similar to is, but instead of returning an i32 answer, they trap on
an invalid value, and return it otherwise.

These could in theory be in a single RefDoThing, with opcodes for both As
and Is, but as the return values are different, that would be a little odd, and
the name would be less clear.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/wasm/wasm-s-parser.cpp b/src/wasm/wasm-s-parser.cpp
index b9927cbc7..5dec22eb3 100644
--- a/src/wasm/wasm-s-parser.cpp
+++ b/src/wasm/wasm-s-parser.cpp
@@ -2236,6 +2236,10 @@ Expression* SExpressionWasmBuilder::makeArrayLen(Element& s) {
   return Builder(wasm).makeArrayLen(ref);
 }
 
+Expression* SExpressionWasmBuilder::makeRefAs(Element& s, RefAsOp op) {
+  return Builder(wasm).makeRefAs(op, parseExpression(s[1]));
+}
+
 // converts an s-expression string representing binary data into an output
 // sequence of raw bytes this appends to data, which may already contain
 // content.