mesa: rename is_in_uniform_block to is_in_buffer_block

Since this now checks if a variable is inside a uniform or a shader
storage block.

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

src/glsl/opt_dead_code.cpp

@@ -115,7 +115,7 @@ do_dead_code(exec_list *instructions, bool uniform_locations_assigned)
              * If the variable is in a uniform block with one of those
              * layouts, do not eliminate it.
              */
-            if (entry->var->is_in_uniform_block()) {
+            if (entry->var->is_in_buffer_block()) {
                const glsl_type *const block_type =
                   entry->var->is_interface_instance()
                   ? entry->var->type : entry->var->get_interface_type();