glsl linker: remove interface block instance names

Convert interface blocks with instance names into flat
interface blocks without an instance name.

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/glsl/ir_optimization.h

@@ -110,6 +110,7 @@ void lower_packed_varyings(void *mem_ctx, unsigned location_base,
                            unsigned locations_used, ir_variable_mode mode,
                            gl_shader *shader);
 bool lower_vector_insert(exec_list *instructions, bool lower_nonconstant_index);
+void lower_named_interface_blocks(void *mem_ctx, gl_shader *shader);
 bool optimize_redundant_jumps(exec_list *instructions);
 bool optimize_split_arrays(exec_list *instructions, bool linked);