pl_u: Use empty shared font if none is available.

GPU: Don't use explicit binding points when uploading the constbuffers to opengl

- Makes games work in lieu of shared_font.bin.

The bindpoints will now be dynamically calculated based on the number of buffers used by the previous shader stage.

fsp_srv: Implement DeleteFile.

 GPU: Use the buffer hints from the shader decompiler to upload only the necessary const buffers for each shader stage

- Used by Binding of Isaac.

GPU: Use the buffer hints from the shader decompiler to upload only the necessary const buffers for each shader stage.

shaders: Expose hints about used const buffers.

GPU: Upload the shader Constant Buffers as SSBOs to the GPU

We're going to need the shader generator to give us a mapping of the actual used const buffers to properly bind them to the shader.

vm_manager: Increase GetTotalMemoryUsage value.

- Gets Binding of Isaac running.

Fix the stuck in fullscreen bug

fsp_srv: Implement IFile::Flush.

OpenGL shader generation part 1

- Tested with Puyo Puyo Tetris and Cave Story+