[wasm] Rename the WASM object to _WASMEXP_.

test/mjsunit/wasm/stackwalk.js

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Flags: --expose-wasm --expose-gc --allow-natives-syntax
 
 load("test/mjsunit/wasm/wasm-constants.js");
 
 function makeFFI(func) {
   var kBodySize = 6;
@@ skipping 20 matching lines @@
     // main body
     kExprCallFunction, 0,       // --
     kExprGetLocal, 0,           // --
     kExprGetLocal, 1,           // --
     // names
     kDeclEnd,
     'f', 'u', 'n', 0,           //  --
     'm', 'a', 'i', 'n', 0       //  --
   );
 
-  var module = WASM.instantiateModule(data, ffi);
+  var module = _WASMEXP_.instantiateModule(data, ffi);
 
   assertEquals("function", typeof module.main);
 
   return module.main;
 }
 
 
 function makeReentrantFFI(func) {
   var main = makeFFI(reenter);
 
@@ skipping 74 matching lines @@
   var gcer = builder(dogc);
   gcer(7, 7);
 
   for (var i = 0; i < 9; i++) {
     gcer(8, 8);
   }
 }
 
 runTest(makeReentrantFFI);
 runTest(makeFFI);