Both code paths will be tested for Windows, macOS, Linux for both LLVM and Subzero backends.

Bug: b/145836207
Change-Id: I707b1551fe1a65549c47a6d7756ab94aeb8d80e2
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/39312
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Ben Clayton <bclayton@google.com>
Reviewed-by: Chris Forbes <chrisforbes@google.com>