If enabled, TRACE macros (in Reactor and Vulkan) will use
OutputDebugString on Windows, printf otherwise, to print the trace. On
Windows, this allows us to use DbgView to monitor and filter the trace
easily, especially useful when running with Chrome, for e.g.

Bug: b/146051794
Change-Id: I15a46f5f0e8bc4e9edcacaf63c15dc605323356d
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/39568
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Tested-by: Antonio Maiorano <amaiorano@google.com>