With this change SwiftShader is buildable for Fuchsia. Integration with
Mozard for EGL will be implemented in a separate CL.

Bug: chromium:800951
Change-Id: I60160c91aecaa6cdc6b07de688ff54b686613ab3
Reviewed-on: https://swiftshader-review.googlesource.com/16148Tested-by: Sergey Ulanov <sergeyu@chromium.org>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>