Usage of VK_EXT_graphics_pipeline_library (Vulkan GPL) causing not insignificant performance loss.

[CNR0706]

Your system information

System Information: https://gist.github.com/CNR0706/e453aa38c4ec3dce4a1761f2bcac6cbb Steam Runtime Diagnostics: https://gist.github.com/CNR0706/e12f63dc649c1aac64c56e689107afe3

• Have you checked for system updates?: [Yes/No] Yes

Please describe your issue in as much detail as possible:

Expected: Game performs the same with or without VK_EXT_graphics_pipeline_library enabled.

What happened: When disabling VK_EXT_graphics_pipeline_library the game gains an extra 20 - 40 FPS depending on the test.

Steps for reproducing this issue:

1. Benchmark game with VK_EXT_graphics_pipeline_library enabled.
2. Set RADV_DEBUG=nogpl variable.
3. Benchmark game with VK_EXT_graphics_pipeline_library disabled.
4. Rerun benchmarks with VK_EXT_graphics_pipeline_library disabled to make sure that shader stuttering is not affecting the results.
5. Compare performance numbers.

Notes: This difference used to be gigantic (100 FPS or more difference). Updates to the game have closed the gap between VK_EXT_graphics_pipeline_library and no VK_EXT_graphics_pipeline_library quite a bit, however there is still a difference that (from what I can tell) definitely should not be there.