linker: Make invalidate_variable_locations available outside the compilation unit

Signed-off-by: Ian Romanick <ian.d.romanick@intel.com>
Tested-by: Tom Stellard <thomas.stellard@amd.com>

src/glsl/linker.h

@@ -30,6 +30,10 @@ extern bool
 link_function_calls(gl_shader_program *prog, gl_shader *main,
 		    gl_shader **shader_list, unsigned num_shaders);
 
+extern void
+link_invalidate_variable_locations(gl_shader *sh, enum ir_variable_mode mode,
+				   int generic_base);
+
 /**
  * Class for processing all of the leaf fields of an uniform
  *