gpu.c: create_host_leaf: move check_scalar_live_ranges into group_references
gpu.c: create_host_leaf: move check_scalar_live_ranges into group_references

The information computed by check_scalar_live_ranges is especially
used by group_references, so it makes sense for group_references
to call this function.  In particular, when we move group_references
to a separate file, check_scalar_live_ranges should move along with it.

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

nicolasvasilache/ppcg,nicolasvasilache/ppcg,Meinersbur/ppcg,Meinersbur/ppcg