Revert of Pull and build shaderc rather than use checked in lib/header

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.
-"""
-
-import argparse
-import os
-import shlex
-import shutil
-import subprocess
-import sys
-
-def main():
-  parser = argparse.ArgumentParser(description='Builds shaderc')
-  parser.add_argument('-s', '--src-dir', required=True, help=
-      'path to shaderc source')
-  parser.add_argument('-t', '--build-type', required=True, help=
-      'Either Release or Debug')
-  parser.add_argument('-a', '--arch-type', required=True, help=
-      'Either x86 or x86_64')
-  parser.add_argument('-o', '--output-dir', required=True, help=
-      'Directory for cmake build')
-  parser.add_argument('-p', '--project_type', required=True, help=
-      'Project type to use. Must be "ninja", "MSVS2013", or "MSVS2015"')
-  args = parser.parse_args()
-
-  args.src_dir = os.path.abspath(args.src_dir)
-  args.output_dir = os.path.abspath(args.output_dir)
-
-  if not os.path.isdir(args.src_dir):
-    sys.exit(args.src_dir + ' is not a directory.')
-    
-  if args.build_type != 'Debug' and args.build_type != 'Release':
-    sys.exit('Invalid build type: ' + args.build_type);
-
-  if args.arch_type == 'x86':
-    vs_arch = ''
-  elif args.arch_type == 'x86_64':
-    vs_arch = ' Win64'
-  else:
-    sys.exit('Invalid arch type: ' + args.arch_type);
-
-  if args.project_type == 'ninja':
-    generator = 'Ninja'
-  elif args.project_type == 'MSVS2013':
-    generator = 'Visual Studio 12 2013' + vs_arch
-  elif args.project_type == "MSVS2015":
-    generator = 'Visual Studio 14 2015' + vs_arch
-  else:
-    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)
-  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()
-