- Take the pipeline's multisample mask into account when generating
cMask
- Wire up cMask to the BuiltInSampleMask input

Bug: b/118386749
Test: dEQP-VK.pipeline.multisample_shader_builtin.sample_mask.pattern.*
Change-Id: Ia65ba31c6a73f87f537164c69e2d3086b82ea27e
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/32528Tested-by: Chris Forbes <chrisforbes@google.com>
Presubmit-Ready: Chris Forbes <chrisforbes@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>