SwiftShader exposes VK_EXT_depth_range_unrestricted which allows depth
values outside [0, 1]. depthBoundsTest code asserted on values outside
that range and were causing test failures.

Bug: b/181655689
Tests: dEQP-VK.pipeline.depth_range_unrestricted.*
Change-Id: Iae9103b802672960f2f0f67710f75165780f1368
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/54110Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Commit-Queue: Sean Risser <srisser@google.com>
Tested-by: Sean Risser <srisser@google.com>