message: [build-swift-cmake] Genericizes build script for use on Windows
  This change depends on swift/utils/build-script also being updated to
  run on Windows.
diff: @@ -70,7 +70,7 @@ def use_gold_linker():
  """@return True if the gold linker should be used; False otherwise."""
  return os.path.isfile("/usr/bin/ld.gold")
  -uname = str(subprocess.check_output(["uname", "-s"])).rstrip()
  +uname = sys.platform
  checkout_git(
  "llvm",
  @@ -183,8 +183,7 @@ else:
  "--install-swift",
  "--install-lldb",
  "--install-destdir",
  - os.getcwd() +
  - "/install",
  + os.path.join(os.getcwd(), "install"),
  "--swift-install-components=compiler;clang-builtin-headers;stdlib;stdlib-experimental;sdk-overlay;editor-integration;tools;testsuite-tools;dev"]
  # build_script_impl_arguments += ["--reconfigure"]
  @@ -206,7 +205,7 @@ else:
  elif args.use_system_debugserver:
  build_script_impl_arguments += ['--lldb-use-system-debugserver']
  -args = ["./swift/utils/build-script"] + \
  +args = ["python" + os.path.join("swift", "utils", "build-script")] + \
  build_script_arguments + ["--"] + build_script_impl_arguments
  print(" ".join(args))
  