Semantic revert of 78304b47 and 7bce5194.  7bce5194 assumed that a
read transition between same layouts is a noop, but that's not true if
said layout is GENERAL.

This is only possible if an image is simultaneously bound as storage and
sampled image.  This bug was discovered by the new syncval VVL warning.

Bug: b/156661359
Change-Id: I05f94160ca1b05b715701564e27fccee31a8aa45
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2404742
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Charlie Lao <cclao@google.com>