Fix warning suppressions leaking under clang.exe

When running clang.exe under Windows, catch.hpp leaks warning
suppressions because it uses `#pragma warning(push)` & `#pragma
warning(pop)` around warning suppressions like `#pragma clang diagnostic
ignore "-Wunused-variable"`, instead of using `#pragma clang diagnostic
push` and `#pragma clang diagnostic pop`.

This fixes that by only defining
`CATCH_INTERNAL_START_WARNINGS_SUPPRESSION` and
`CATCH_INTERNAL_STOP_WARNINGS_SUPPRESSION` to be the cl.exe variants if
`defined(_MSC_VER) && !defined(__clang__)`.

0 files changed, 0 insertions, 0 deletions