Add the same flags for the c++ compiler as they are already defined for the c compiler

Change-Id: If3d42a6b3ad361c8a11b4eee8dd17be0e58d9192
Reviewed-by: Fabian Bumberger <fbumberger@rim.com>
Reviewed-by: Bernd Weimer <bweimer@blackberry.com>
Reviewed-by: Thomas McGuire <thomas.mcguire@kdab.com>