nir/print: Use src_type when printing consts in SSA uses

nir/print: Use src_type when printing consts in SSA uses

If the src_type is not available, untie by looking at the results from
nir_gather_ssa_types(). If that is ambiguous, just pick uint.

Now in print_const_from_load() when the type is invalid, print the full
constant form (with both padded hex and float); when the passed type
is valid, print the terse form based on it.

Reviewed-by: Jesse Natalie <jenatali@microsoft.com>
Acked-by: Emma Anholt <emma@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/23562>