Coroutines have a larger performance overhead to regular functions.
If a rr::Coroutine does not call Yield(), then keep it as a regular function, and stub `coroutine_await` and `coroutine_destroy`.

Bug: b/135609394
Bug: b/137167505
Change-Id: Id890e86eb3602f9cd9ed4e68e50c68a98705c753
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/33950Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Chris Forbes <chrisforbes@google.com>
Tested-by: Ben Clayton <bclayton@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>