message: Pass -toolchain-stdlib-rpath.
diff: @@ -110,11 +110,14 @@ def use_support_substitutions(config):
  os.path.join(os.path.dirname(config.lldb_libs_dir),
  'lldb-test-build.noindex',
  'module-cache-clang')]
  + swift_driver_args = []
  if platform.system() in ['Darwin']:
  swift_args += ['-sdk', sdk_path]
  + swift_driver_args += ['-toolchain-stdlib-rpath']
  tools = [
  ToolSubst(
  - '%target-swiftc', command=config.swiftc, extra_args=swift_args),
  + '%target-swiftc', command=config.swiftc,
  + extra_args=swift_args + swift_driver_args),
  ToolSubst(
  '%target-swift-frontend', command=config.swiftc[:-1],
  extra_args=(['-frontend'] + swift_args))
  