The TEST_INCLUDE_FILE(S) directory properties were written verbatim into
CTestTestfile.cmake, so a $<CONFIG>-parameterized include path could not
select a per-configuration script and failed at ctest time.
Evaluate generator expressions per include entry in
cmLocalGenerator::GenerateTestFiles():
* Entries without a generator expression are emitted unchanged.
* On single-config generators a genex entry is evaluated once and
emitted as one unconditional include.
* On multi-config generators it is evaluated for every configuration;
a config-independent result collapses to one unconditional include,
otherwise each non-empty per-config result is guarded by a
CTEST_CONFIGURATION_TYPE branch, mirroring add_test(). An entry that
evaluates to empty adds no include.
Promote cmScriptGenerator::CreateConfigTest to a public static helper so
the include guards reuse the exact add_test() config-test encoding; the
instance overloads now delegate to it. Evaluated results are quoted via
cmScriptGenerator::Quote, while plain entries keep their raw
serialization.
Fixes: #27941
Daksh Mamodiya
scivision
AJIOB
Brad King
Craig Scott
Matthew Woehlke