[build] Enable -Wlong-long compiler warning.

gypfiles/standalone.gypi

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 689 matching lines @@
         ],
       },  # target_defaults
     }],  # OS=="mac"
     ['OS=="linux" or OS=="freebsd" or OS=="openbsd" or OS=="solaris" \
        or OS=="netbsd" or OS=="aix"', {
       'target_defaults': {
         'cflags': [
           '-Wall',
           '<(werror)',
           '-Wno-unused-parameter',
-          '-Wno-long-long',
           '-pthread',
           '-pedantic',
           '-Wmissing-field-initializers',
           '-Wno-gnu-zero-variadic-macro-arguments',
         ],
         'cflags_cc': [
           '-Wnon-virtual-dtor',
           '-fno-exceptions',
           '-fno-rtti',
           '-std=gnu++11',
@@ skipping 730 matching lines @@
               '-fsanitize=cfi-vcall',
               '-fsanitize=cfi-derived-cast',
               '-fsanitize=cfi-unrelated-cast',
             ],
           }],
         ],
       },
     }],
   ],
 }