- stop passing explicit libpaths via `CMAKE_SHARED_LINKER_FLAGS` and
`CMAKE_EXE_LINKER_FLAGS`. `link_directories()` is doing that already.
- use `curl_required_libpaths()` to pass libpaths to the feature test.
Reported-by: Daniel Engberg
Fixes#15536
Also fixes GSS feature detection with non-gcc/clang compilers,
such as MSVC.
- add libpaths to `CURL_LIBPATHS`.
- move `GSS_CFLAGS`, `GSS_LDFLAGS` stringifications to FindGSS.
To match the `CFLAGS` format returned by the rest of Find modules.
- reorder calls to match other dependencies.
- don't extend system `LDFLAGS` when FindGSS did not return any.
- ignore `LDFLAGS` when detecting GSS via `pkg-config`. `LDFLAGS` holds
a copy of libpaths and libs in this case. Ignore those to avoid these
duplicates making into `libcurl.pc` and `curl-config`. Also syncing
behavior with other Find modules which also ignore raw `LDFLAGS`.
- ignore raw `LDFLAGS` coming from `krb5-config --libs`. FindGSS
no longer returns dependency-specific `LDFLAGS` after this. Syncing
behavior with other Find modules.
- reduce scope of checker state push/pop/set.
Closes#15545
e0e93d4314