InstCombine: Match pattern that appears in clang's __builtin_isnormal

and (fcmp ord x, 0), (fcmp u* x, inf) -> fcmp o* x, inf
and (fcmp ord x, 0), (fcmp u* fabs(x), inf) -> fcmp o* x, inf

Clang emits this peculiar pattern as an isfinite check in
__builtin_isnormal which can be simplified. We should fix clang to
emit this in the first place, but should also fold it here.