Use LOCALAPPDATA for system cache on windows (#2297)
Use LOCALAPPDATA for system cache on windows (#2297)

Use `%LOCALAPPDATA%` for `.pub-cache` on windows if `.pub-cache` doesn't already existing in  `%APPDATA%`.

Using `%LOCALAPPDATA%` is better because it's not copied when users roam between devices.
dart-lang/pub,dart-lang/pub