This has really spotty coverage [see VK-GL-CTS #1770], but is legal.

Test: dEQP-VK.api.descriptor_set.descriptor_set_layout_lifetime.graphics
Change-Id: I1452fb7a2146e882f6d792d153135ff8b474aca4
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/31069Tested-by: Chris Forbes <chrisforbes@google.com>
Presubmit-Ready: Chris Forbes <chrisforbes@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>