amd/common: Introduce ac_get_fs_input_vgpr_cnt.

Add a function called ac_get_fs_input_vgpr_cnt which will return
the number of input VGPRs used by an AMD shader. Previously,
radv and radeonsi had the same code duplicated, but this commit also
allows them to share this code.

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

src/amd/common/ac_shader_util.h

@@ -28,6 +28,7 @@
 #include <stdint.h>
 
 #include "amd_family.h"
+#include "ac_binary.h"
 #include "compiler/nir/nir.h"
 
 enum ac_image_dim {
@@ -63,4 +64,9 @@ enum ac_image_dim
 ac_get_image_dim(enum chip_class chip_class, enum glsl_sampler_dim sdim,
 		 bool is_array);
 
+unsigned
+ac_get_fs_input_vgpr_cnt(const struct ac_shader_config *config,
+			 signed char *face_vgpr_index,
+			 signed char *ancillary_vgpr_index);
+
 #endif