Summary

• treat failed try_run compilations as failures before consulting the run result
• only add HAVE_* definitions when both compilation succeeds and the probe executable returns 0

Rationale

• fixes [BUG] incorrect logic of checking the return of try_run() in CXXFeatureCheck.cmake when compile fails #2036 by ensuring platform feature checks don’t report success when the probe source fails to compile (observed with GNU regex on AIX)

Changes

• gate the previously unconditional RUN_* EQUAL 0 check with the corresponding COMPILE_* flag
• streamline the failure messages so compile errors are always reported when the probe build fails

Fixes #2036