Type decorations may be ignored when using multiple OpAccessChains.

Bug: angleproject:4492
Change-Id: I2e51af600394a69cb5f7e02228ca7e4fd1c826e0
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2105529Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>