Prefer overrides with exact name matches over generic name matches.
For instance, if we override both ClearBufferfi and ClearBuffer, then
ClearBuffer{i f ui}v will be overriden be ClearBuffer and
ClearBufferfi will be overriden by ClearBufferfi. This allows us to
specialize overrides when necessary.
Implemented Whole Framebuffer commands according to the OpenGL 4.4
specification, section 17.4.