This should fix kits complaining about wrongly set C compilers and
ABI incompatibility between C and C++ compilers.

Task-number: QTCREATORBUG-17165
Task-number: QTCREATORBUG-17166
Change-Id: Ia002490b471e0f5306c3a76b27158869920452ed
Reviewed-by: BogDan Vatra <bogdan@kdab.com>