Add --enable-wasm to wasm tests.

test/mjsunit/wasm/calls.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
+
 load("test/mjsunit/wasm/wasm-constants.js");
 
 var module = (function () {
   var kBodySize = 5;
   var kNameOffset = 21 + kBodySize + 1;
 
   return WASM.instantiateModule(bytes(
     // -- memory
     kDeclMemory,
     12, 12, 1,
@@ skipping 119 matching lines @@
     'f', 'l', 't', 0              // name
   );
 
   var module = WASM.instantiateModule(data);
 
   assertEquals("function", typeof module.flt);
   assertEquals(1, module.flt(-2, -1));
   assertEquals(0, module.flt(7.3, 7.1));
   assertEquals(1, module.flt(7.1, 7.3));
 })();