intel/fs: Add helper to get prog_offset and simd_size

This indirection will be used by the variable group size case in a
later change.

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5142>

src/intel/compiler/brw_compiler.h

@@ -942,6 +942,15 @@ struct brw_cs_prog_data {
    } binding_table;
 };
 
+static inline uint32_t
+brw_cs_prog_data_prog_offset(const struct brw_cs_prog_data *prog_data,
+                             unsigned dispatch_width)
+{
+   /* For now, we generate code for one program, so offset is always 0. */
+   assert(dispatch_width == prog_data->simd_size);
+   return 0;
+}
+
 /**
  * Enum representing the i965-specific vertex results that don't correspond
  * exactly to any element of gl_varying_slot.  The values of this enum are
@@ -1500,6 +1509,11 @@ unsigned
 brw_cs_push_const_total_size(const struct brw_cs_prog_data *cs_prog_data,
                              unsigned threads);
 
+unsigned
+brw_cs_simd_size_for_group_size(const struct gen_device_info *devinfo,
+                                const struct brw_cs_prog_data *cs_prog_data,
+                                unsigned group_size);
+
 /**
  * Return true if the given shader stage is dispatched contiguously by the
  * relevant fixed function starting from channel 0 of the SIMD thread, which