Descriptor set layouts and pools are very tightly coupled, since their
binding types and counts must match to ensure the number of available
descriptor sets within a pool remains accurate. To enforce this, the
descriptor pools will now keep a copy of the VkDescriptorSetLayout that
the pool was created for, which is verified when a descriptor set is
allocated from the pool. If the handles don't match, an ASSERT() will
fire.

Bug: angleproject:5033
Test: CQ
Change-Id: I4faf82c24f31052e57b656c968788bb0c131b619
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2407282Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com>
Reviewed-by: Charlie Lao <cclao@google.com>
Commit-Queue: Tim Van Patten <timvp@google.com>