ANGLE can sometimes hold on to deleted shaders while they're still in
use. This would happen when re-capturing captured application. A bunch
of shaders would be still around after used in the program linking
step because they are still attached to the program. Fix this by not
skipping the capture for shader that have been deleted but are still
in the resource map. Noticed while capturing the T-Rex replay.

Bug: angleproject:5134
Change-Id: I04e3e96b43e445d7b467e6db0325ecd0d821549d
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2449162
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Cody Northrop <cnorthrop@google.com>
Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com>