Created by: kbrenneman
Added a new function to libGLdispatch, __glDispatchForceUnpatch, which forces it to unpatch the OpenGL entrypoints before libEGL or libGLX can unload the vendor library that patched them.
If a vendor patches the OpenGL entrypoints, libGLdispatch doesn't unpatch them when that vendor's context is no longer current, because that adds too much overhead to repeated MakeCurrent+LoseCurrent calls. But, that also means that the patch callbacks end up being dangling pointers after the vendor library is unloaded.
This mainly shows up at process termination when a process loads both libEGL and libGLX, because __glxFini and __eglFini will both call the vendor's threadAttach callback.