LibGL: Implement glColorMask

Author: https://github.com/Quaker762
Commit: 8157e7740b
Pull-request: https://github.com/SerenityOS/serenity/pull/9381
Reviewed-by: https://github.com/sunverwerth ✅

Userland/Libraries/LibGL/SoftwareRasterizer.h

@@ -28,6 +28,7 @@ struct RasterizerOptions {
     bool enable_blending { false };
     GLenum blend_source_factor { GL_ONE };
     GLenum blend_destination_factor { GL_ONE };
+    u32 color_mask { 0xffffffff };
 };
 
 class SoftwareRasterizer final {