dEQP has no test coverage for this. Filed VK-GL-CTS #1728 to fix that.

Bug: b/126873455
Change-Id: I69524d0f4d5d15356eedd105645637af1a4f0f0f
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/28608Tested-by: Ben Clayton <bclayton@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>