This first implementation ignores all optional functionality, so
this is a very bare-bones implementation of VK_EXT_debug_utils.

Bug: b/119321052
Change-Id: I8ef189b957b6d1b433846de945b7852c3d6e8190
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/46968
Presubmit-Ready: Alexis Hétu <sugoi@google.com>
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>