This was causing the dEQP-VK.memory_model.message_passing.core11.u32.coherent.fence_fence.atomicwrite.workgroup.*
tests to read out of bounds when robust buffer access is disabled.

Bug: b/136561217
Change-Id: I4891f5cd531e99b3dd87b4b84ae545ba47355875
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/33528Reviewed-by: Chris Forbes <chrisforbes@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>