glsl: add new gl_nir_link_glsl() helper

This will allow us to do some linking in NIR that was previously
done by the GLSL IR linker. To start with this just has calls for
linking atomics.

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>

src/compiler/glsl/gl_nir_linker.c

@@ -581,3 +581,15 @@ gl_nir_link_spirv(struct gl_context *ctx, struct gl_shader_program *prog,
 
    return true;
 }
+
+bool
+gl_nir_link_glsl(struct gl_context *ctx, struct gl_shader_program *prog)
+{
+   gl_nir_link_assign_atomic_counter_resources(ctx, prog);
+   gl_nir_link_check_atomic_counter_resources(ctx, prog);
+
+   if (prog->data->LinkStatus == LINKING_FAILURE)
+      return false;
+
+   return true;
+}