glsl: Track whether uniforms are active per stage

for finer granularity state flagging

v2: Marek - use a bitmask, add shader cache support

Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>

src/compiler/glsl/link_uniforms.cpp

@@ -766,6 +766,8 @@ private:
       this->uniforms[id].opaque[shader_type].index = ~0;
       this->uniforms[id].opaque[shader_type].active = false;
 
+      this->uniforms[id].active_shader_mask |= 1 << shader_type;
+
       /* This assigns uniform indices to sampler and image uniforms. */
       handle_samplers(base_type, &this->uniforms[id], name);
       handle_images(base_type, &this->uniforms[id], name);