[wasm] Rename _WASMEXP_ object to Wasm.

test/mjsunit/wasm/embenchen/zlib.js

Index: test/mjsunit/wasm/embenchen/zlib.js
diff --git a/test/mjsunit/wasm/embenchen/zlib.js b/test/mjsunit/wasm/embenchen/zlib.js
index c7515f08a19cde92ba2a9b38beebc4aecf77ece7..9c0d30a813b519f91abaffb3e3ff208398ebe80a 100644
--- a/test/mjsunit/wasm/embenchen/zlib.js
+++ b/test/mjsunit/wasm/embenchen/zlib.js
@@ -5687,7 +5687,7 @@ function asmPrintFloat(x, y) {
   Module.print('float ' + x + ',' + y);// + ' ' + new Error().stack);
 }
 // EMSCRIPTEN_START_ASM
-var asm = _WASMEXP_.instantiateModuleFromAsm((function Module(global, env, buffer) {
+var asm = Wasm.instantiateModuleFromAsm((function Module(global, env, buffer) {
   'use asm';
   var HEAP8 = new global.Int8Array(buffer);
   var HEAP16 = new global.Int16Array(buffer);