glsl: add extra pp tokens workaround and enable for CoR

The CTS now tests to make sure these are not allowed. However, previously
drivers (including Mesa) would allow them to exist and just issue a
warning. Some old applications such as Champions of Regnum seem to
depend on this.

Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/422

Fixes: 43047384c331 ("glsl/glcpp: Promote "extra token at end of directive" from warning to error")

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7361>
9 files changed