Pack handle type enum for glImportMemoryFd & glImportSemaphoreFd Bug: angleproject:3289 Change-Id: Ic20b1d55641494b46622e1e28d93e2ca30655ea6 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1566143 Commit-Queue: Michael Spang <spang@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>