This is a first, rough, implementation of the OpenCL.Debug.100 extension instruction set.

This is incomplete, and likely buggy.

It does however implement enough to perform single line stepping through hand-crafted HLSL, with basic variable inspection.

Many tests and fixes to come...

Bug: b/145351270
Change-Id: Ia570f5b22a8b3ce39df0438ca3c6700d1a00d014
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/40268Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Ben Clayton <bclayton@google.com>