In GL ES, depth is always clamped to [0,1].
The same is true in Vulkan, but not for implementations affected by
Nvidia bug 3171019. This patch implements a workaround.
The workaround introduced test failures on Linux with Nvidia Quadro P400
and driver version 418.56, so it's only applied conditionally, and as a
result the test failure expectations are not removed completely.

Bug: angleproject:3970
Change-Id: I0d9f855d7f3df72fea4af9f9b134ae3177cf820d
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2514377
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>