Added validating JSON parser mode to parser.

test/mjsunit/mirror-script.js

Index: test/mjsunit/mirror-script.js
diff --git a/test/mjsunit/mirror-script.js b/test/mjsunit/mirror-script.js
index 3208f16c38a9e5aab56eaac780d6efce7e39f176..8631028e4e3e94af0aea3c3e5c0341e19f498105 100644
--- a/test/mjsunit/mirror-script.js
+++ b/test/mjsunit/mirror-script.js
@@ -87,8 +87,8 @@ testScriptMirror(function(){}, 'mirror-script.js', 100, 2, 0);
 testScriptMirror(Math.sin, 'native math.js', -1, 0, 0);
 testScriptMirror(eval('(function(){})'), null, 1, 2, 1, '(function(){})', 87);
 testScriptMirror(eval('(function(){\n  })'), null, 2, 2, 1, '(function(){\n  })', 88);
-testScriptMirror(%CompileString("({a:1,b:2})", true), null, 1, 2, 2, '({a:1,b:2})');
-testScriptMirror(%CompileString("({a:1,\n  b:2})", true), null, 2, 2, 2, '({a:1,\n  b:2})');
+testScriptMirror(%CompileString('{"a":1,"b":2}', true), null, 1, 2, 2, '{"a":1,"b":2}');
+testScriptMirror(%CompileString('{"a":1,\n  "b":2}', true), null, 2, 2, 2, '{"a":1,\n  "b":2}');
 
 // Test taking slices of source.
 var mirror = debug.MakeMirror(eval('(function(){\n  1;\n})')).script();