Add support for flag in driver_arguments

Author: edymtt

utils/build-script

@@ -498,6 +498,8 @@ class BuildScriptInvocation(object):
             impl_args += ["--skip-build-watchos-simulator"]
         if not args.build_android:
             impl_args += ["--skip-build-android"]
+        if not args.build_clang_tools_extra:
+            impl_args += ["--skip-build-clang-tools-extra"]
 
         if not args.test and not args.long_test and not args.stress_test:
             impl_args += ["--skip-test-swift"]

utils/build_swift/driver_arguments.py

@@ -615,6 +615,11 @@ def create_argument_parser():
     option(['--build-libparser-only'], store_true('build_libparser_only'),
            help='build only libParser for SwiftSyntax')
 
+    option('--skip-build-clang-tools-extra',
+           toggle_false('build_clang_tools_extra'),
+           default=True,
+           help='skip building clang-tools-extra as part of llvm')
+
     # -------------------------------------------------------------------------
     in_group('Extra actions to perform before or in addition to building')
 

utils/build_swift/tests/expected_options.py

@@ -56,6 +56,7 @@
     'build_android': False,
     'build_args': [],
     'build_benchmarks': True,
+    'build_clang_tools_extra': True,
     'build_cygwin': True,
     'build_external_benchmarks': False,
     'build_foundation': False,
@@ -553,6 +554,8 @@ class BuildScriptImplOption(_BaseOption):
     DisableOption('--skip-test-swiftevolve', dest='test_swiftevolve'),
     DisableOption('--skip-test-toolchain-benchmarks',
                   dest='test_toolchainbenchmarks'),
+    DisableOption('--skip-build-clang-tools-extra',
+                  dest='build_clang_tools_extra'),
 
     ChoicesOption('--android-ndk-gcc-version',
                   choices=['4.8', '4.9']),