Revert various gcc workarounds on Windows
Here we revert two hacks introduced to work around gcc's lack of proper Unicode support on Windows:
- Revert the workaround introduced in f63c8ef3, which taught our response file logic to write response files with the
latin1
encoding to workaroundgcc
's lacking Unicode support. This is now no longer necessary (and in fact actively unhelpful) since we rather use Clang. - As noted in #12971 (closed), we previously used
show
, which resulted in inappropriate escaping of non-ASCII characters.
Fixes #12971 (closed).