spirv: Only require bare types to match when copying variables

OpCopyMemory doesn't care about mismatched decorations, only about
matching types.

Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/3418
Fixes: bf1a1eed882980a1cd08482386e3a001ce64a5a4
Signed-off-by: Danylo Piliaiev <danylo.piliaiev@globallogic.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6344>
1 file changed