tests: reduce template recursion depth
tests: reduce template recursion depth

With a long typelist the recursion depth can easily get too deep. By
handling two types per template instantiation I was able to reduce the
depth by a factor of 2.

Signed-off-by: Matthias Kretz <372ea4eca737a13cd010ee806d4ce7b98ee71550@kde.org>

chr-engwer/Vc,VcDevel/Vc,VcDevel/Vc,chr-engwer/Vc,VcDevel/Vc,VcDevel/Vc,chr-engwer/Vc