Capture/Replay: Special-case EGL image attribute pointer write If we don't special case this, the taken code path may end up writing "(nil)" if we have a null pointer, and compilation of the test will fail. Bug: angleproject:7793 Change-Id: Ic9fe9ccca0304069adbbb996666bc643e7d29278 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3990758 Reviewed-by: Cody Northrop <cnorthrop@google.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Gert Wollny <gert.wollny@collabora.com>