configure.ac: improve detection of 5-argument setLangDefaults
configure.ac: improve detection of 5-argument setLangDefaults

In particular, include all the required header files to avoid
the test failing because of issues unrelated to the number
of arguments of CompilerInvocation::setLangDefaults.

Signed-off-by: Sven Verdoolaege <e5350bbed4977f5eb8ae1dc6abd9ae59d21ace75@kotnet.org>

PollyLabs/isl,UBERTC/isl,UBERTC/isl,PollyLabs/isl,PollyLabs/isl,nicolasvasilache/isl,PollyLabs/isl,tobig/isl,UBERTC/isl,nicolasvasilache/isl,inducer/isl-mirror,Meinersbur/isl,tobig/isl,Meinersbur/isl,UBERTC/isl,inducer/isl-mirror,PollyLabs/isl,tobig/isl,tobig/isl,inducer/isl-mirror,inducer/isl-mirror,nicolasvasilache/isl,nicolasvasilache/isl,inducer/isl-mirror,Meinersbur/isl,Meinersbur/isl,nicolasvasilache/isl