Add LC_ALL=C to gcc linker wrappers to speed up links

build/toolchain/gcc_link_wrapper.py

 #!/usr/bin/env python
 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Runs a linking command and optionally a strip command.
 
 This script exists to avoid using complex shell commands in
 gcc_toolchain.gni's tool("link"), in case the host running the compiler
 does not have a POSIX-like shell (e.g. Windows).
 """
 
 import argparse
+import os
 import subprocess
 import sys
 
 
 # When running on a Windows host and using a toolchain whose tools are
 # actually wrapper scripts (i.e. .bat files on Windows) rather than binary
 # executables, the "command" to run has to be prefixed with this magic.
 # The GN toolchain definitions take care of that for when GN/Ninja is
 # running the tool directly.  When that command is passed in to this
 # script, it appears as a unitary string but needs to be split up so that
@@ skipping 16 matching lines @@
                       help='Executable file produced by linking command',
                       metavar='FILE')
   parser.add_argument('--output',
                       required=True,
                       help='Final output executable file',
                       metavar='FILE')
   parser.add_argument('command', nargs='+',
                       help='Linking command')
   args = parser.parse_args()
 
-  # First, run the actual link.
-  result = subprocess.call(CommandToRun(args.command))
+  # Work-around for gold being slow-by-default. http://crbug.com/632230
+  fast_env = dict(os.environ)
+  fast_env['LC_ALL'] = 'C'
+  result = subprocess.call(CommandToRun(args.command), env=fast_env)
   if result != 0:
     return result
 
   # Finally, strip the linked executable (if desired).
   if args.strip:
     result = subprocess.call(CommandToRun([
         args.strip, '--strip-unneeded', '-o', args.output, args.unstripped_file
         ]))
 
   return result
 
 
 if __name__ == "__main__":
   sys.exit(main())