Add support for reference types proposal (#2451)

This adds support for the reference type proposal. This includes support
for all reference types (`anyref`, `funcref`(=`anyfunc`), and `nullref`)
and four new instructions: `ref.null`, `ref.is_null`, `ref.func`, and
new typed `select`. This also adds subtype relationship support between
reference types.

This does not include table instructions yet. This also does not include
wasm2js support.

Fixes #2444 and fixes #2447.

1 files changed, 3 insertions, 0 deletions

diff --git a/src/ir/ExpressionAnalyzer.cpp b/src/ir/ExpressionAnalyzer.cpp
index 7355d1856..4b9869ddd 100644
--- a/src/ir/ExpressionAnalyzer.cpp
+++ b/src/ir/ExpressionAnalyzer.cpp
@@ -218,6 +218,9 @@ template<typename T> void visitImmediates(Expression* curr, T& visitor) {
       visitor.visitInt(curr->op);
       visitor.visitNonScopeName(curr->nameOperand);
     }
+    void visitRefNull(RefNull* curr) {}
+    void visitRefIsNull(RefIsNull* curr) {}
+    void visitRefFunc(RefFunc* curr) { visitor.visitNonScopeName(curr->func); }
     void visitTry(Try* curr) {}
     void visitThrow(Throw* curr) { visitor.visitNonScopeName(curr->event); }
     void visitRethrow(Rethrow* curr) {}