Add comment about branch of wabt that supports ref.test

Author: hoodmane

Python/emscripten_trampoline.c

@@ -26,11 +26,9 @@ EM_JS(CountArgsFunc, _PyEM_GetCountArgsPtr, (), {
 // Binary module for the checks. It has to be done in web assembly because
 // clang/llvm have no support yet for the reference types yet. In fact, the wasm
 // binary toolkit doesn't yet support the ref.test instruction either. To
-// convert the following module to the binary, my approach is to find and
-// replace "ref.test $type" -> "drop i32.const n" on the source text. This
-// results in the bytes "0x1a, 0x41, n" where we need the bytes "0xfb, 0x14, n"
-// so doing a find and replace on the output from "0x1a, 0x41" -> "0xfb, 0x14"
-// gets us the output we need.
+// convert the following textual wasm to a binary, you can build wabt from this
+// branch: https://github.com/WebAssembly/wabt/pull/2529 and then use that
+// wat2wasm binary.
 //
 // (module
 //     (type $type0 (func (param) (result i32)))