Implement resource management for GL_EXT_memory_object This implements glCreateMemoryObjectsEXT, glDeleteMemoryObjectsEXT, and glIsMemoryObjectEXT. It's not possible to do anything useful with them yet. Bug: angleproject:3289 Change-Id: I8882b657e9de564b5f97f8dea87838f67b1928f8 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1552025 Commit-Queue: Michael Spang <spang@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>