Try compiling V8 for Mac with -O3 when using the v8.gyp file.

Review URL: http://codereview.chromium.org/174138

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@2730 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

tools/gyp/v8.gyp

@@ -101,6 +101,11 @@
               '-fno-rtti',
             ],
           }],
+	  ['OS=="mac"', {
+	    'xcode_settings': {
+	      'GCC_OPTIMIZATION_LEVEL': '3',
+	    },
+	  }],
           ['OS=="win"', {
             'msvs_configuration_attributes': {
               'OutputDirectory': '$(SolutionDir)$(ConfigurationName)',