Ensure texture_border_clamp entry points consistency Invalid calls must not reach the context. Affects all entry points added by the texture_border_clamp extensions. Bug: angleproject:406922380 Change-Id: I5e2a58ef70396e27f1ae681595359690e1ca14f4 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/6417005 Commit-Queue: Alexey Knyazev <lexa.knyazev@gmail.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>