Unsuccessful routine creation is a bug that must be caught instead of
being silently ignored.

Bug: b/148295813
Change-Id: Ic718f0420d6833362944c96a3d172813eba3c207
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/40568Tested-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>