vk::trace is pretty much a no-op, and hides warnings and errors.
If we do get an error, spirv-opt tends to eat the SPIR-V, leading to a cryptic 'ASSERT(code.size() > 0)' crash.

Bug: b/139424793
Change-Id: Ie6f3819265ad0e32e85d4c6b1824d263d9fde02f
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/35209
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Ben Clayton <bclayton@google.com>