Merge pull request #2314 from drewcrawford/build-script-impl

[build-script-migrator] fix TypeError

Author: gribozavr

utils/swift_build_support/swift_build_support/migration.py

@@ -31,7 +31,7 @@ def parse_args(parser, argv):
         build-script -RT -- --reconfigure
     """
     args, unknown_args = parser.parse_known_args(
-        arg for arg in argv if arg != '--')
+        list(arg for arg in argv if arg != '--'))
     args.build_script_impl_args = unknown_args
     return args