Add Xcode lastKnownFileType mappings for .js and .py files.
Add Xcode lastKnownFileType mappings for .js and .py files.

old8xp/gyp_from_google,old8xp/gyp_from_google,old8xp/gyp_from_google,old8xp/gyp_from_google,old8xp/gyp_from_google