Sync border color on format updates When a texture is redefined, its border color should be resynced because of format-specific adjustments. Used memcmp for comparing ColorGeneric structs. Bug: angleproject:7969 Change-Id: If0e3e0bc7761c26dab6d00ab24462c789f5b90bb Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4935866 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Alexey Knyazev <lexa.knyazev@gmail.com>