Delete stale unused proc table functions. These were orphaned and unused after we shifted the proc table generator to split between WGL and EGL. Bug: angleproject:3533 Change-Id: I0bf6df438ba431a0cac0a1f89eabc13c67a0f676 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1895760 Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Jamie Madill <jmadill@chromium.org>