Draft: mesa: Implement GL_EXT_multisample_compatibility
Big GL has an enable for turning multisample rendering on or off for a given framebuffer. So did GLES1! GLES2 took it out for some reason, and this (trivially) adds it back. We enable it unconditionally, matching GL_ARB_multisample.
Truly excited to see what this breaks in CI.
Edited by Adam Jackson