Merge topic 'test-objc'

bb2370842f Tests: Simplify RunCMake.try_compile compiler inspection
1abcb094a7 Tests: Fix logic to enable RunCMake.try_compile OBJC/OBJCXX cases
b641a80d55 Tests: Factor out a CMake_TEST_OBJC variable for OBJC/OBJCXX test conditions

Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Merge-request: !7855