spirv: Implement rescaling patching

src/shader_recompiler/runtime_info.h

@@ -63,6 +63,8 @@ struct RuntimeInfo {
     std::array<AttributeType, 32> generic_input_types{};
     VaryingState previous_stage_stores;
 
+    u32 num_textures{};
+
     bool convert_depth_mode{};
     bool force_early_z{};