amd/common: Extract some helper functions to ac_shader_util.

This commit moves ac_get_tbuffer_format, ac_get_sampler_dim and
ac_get_image_dim into ac_shader_util, thus enabling them to be used
by compilers other than LLVM.

Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
5 files changed