RefFunc: Validate that the type is non-nullable, and avoid possible bugs in the builder (#3790)

The builder can receive a HeapType so that callers don't need to set non-nullability
themselves.

Not NFC as some of the callers were in fact still making it nullable.

1 files changed, 3 insertions, 1 deletions

diff --git a/test/binaryen.js/expressions.js b/test/binaryen.js/expressions.js
index 68f5c8cee..b458355cd 100644
--- a/test/binaryen.js/expressions.js
+++ b/test/binaryen.js/expressions.js
@@ -1448,7 +1448,9 @@ console.log("# RefFunc");
   assert(theRefFunc instanceof binaryen.RefFunc);
   assert(theRefFunc instanceof binaryen.Expression);
   assert(theRefFunc.func === func);
-  assert(theRefFunc.type === binaryen.funcref);
+  // TODO: check the type. the type is (ref func), that is, a non-nullable func,
+  //       which differs from funcref. we don't have the ability to create such
+  //       a type in the C/JS APIs yet.
 
   theRefFunc.func = func = "b";
   assert(theRefFunc.func === func);