Reserve 1GB at the base of the address space of linux nacl_helper for Native Client module.

tools/ld_bfd/ld

 #!/usr/bin/python
 # Copyright (c) 2011 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.
 
 """Wrapper for invoking the BFD loader
 
 A simple script to invoke the bfd loader instead of gold, removing
 threading command line options that the bfd loader doesn't support.
 Because this script is invoked from gcc via the -B flag, it needs
@@ skipping 16 matching lines @@
     print "ld_bfd/ld: using ld"
     sys.exit(subprocess.call(args))
   # found the BFD loader, so use it
   args = list()
   args.append("/usr/bin/ld.bfd")
   for arg in sys.argv[1:]:
     if arg == "-Wl,--threads" or arg == "--threads":
       continue
     if arg == "-Wl,--thread-count=4" or arg == "--thread-count=4":
       continue
+    if arg == "--icf=none":
+      continue
     args.append(arg)
   print("ld_bfd/ld: exec ", args)
   sys.exit(subprocess.call(args))
 
 if __name__ == "__main__":
   main()