Follow the spec more closely and only reserve IDs of vertex arrays and
transform feedback objects before binding.  This saves memory and allows
the glIs* calls to succeed.

BUG=angleproject:1218
BUG=angleproject:1101

Change-Id: I7bf99870a7c93f5545325785cbecd891c6b77f8a
Reviewed-on: https://chromium-review.googlesource.com/316402Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>