Update shaderc to ToT.

tools/build_shaderc.py

 #!/usr/bin/python
 
 # Copyright 2016 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 
 """
 Script to build the shaderc library.
@@ skipping 46 matching lines @@
     sys.exit('Invalid project type: ' + args.project_type);
 
   if not os.path.isdir(args.output_dir):
     try:
       os.makedirs(args.output_dir)
     except os.error:
       sys.exit('Error creating output dir ' + args.output_dir)
 
   try:
     subprocess.check_call(['cmake', '-G', generator,
-        '-DSPIRV_SKIP_EXECUTABLES=ON', args.src_dir], cwd=args.output_dir)
+        '-DSPIRV_SKIP_EXECUTABLES=ON', '-DSHADERC_ENABLE_SHARED_CRT=ON',
+        args.src_dir], cwd=args.output_dir)
   except subprocess.CalledProcessError as error:
     sys.exit('Error (ret code: {code}) calling "{cmd}" in {dir}'.format(
         code = error.returncode, cmd = error.cmd, dir = args.src_dir))
 
   try:
     subprocess.check_call(['cmake', '--build', args.output_dir, '--config',
         args.build_type], cwd=args.output_dir)
   except subprocess.CalledProcessError as error:
     sys.exit('Error (ret code: {code}) calling "{cmd}" in {dir}'.format(
         code = error.returncode, cmd = error.cmd, dir = args.src_dir))
 
 if __name__ == '__main__':
   main()