[wasm] Rename _WASMEXP_ object to Wasm.

test/mjsunit/wasm/embenchen/corrections.js

Index: test/mjsunit/wasm/embenchen/corrections.js
diff --git a/test/mjsunit/wasm/embenchen/corrections.js b/test/mjsunit/wasm/embenchen/corrections.js
index cd957ec138d187f8f7fba5cd56fc110b97fbb3c5..23bec5f5c7d217fc69e917e6b40e8232a6f800d9 100644
--- a/test/mjsunit/wasm/embenchen/corrections.js
+++ b/test/mjsunit/wasm/embenchen/corrections.js
@@ -5452,7 +5452,7 @@ 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);