* Implementations must ignore basePipelineIndex & basePipelineHandle
  if VK_PIPELINE_CREATE_DERIVATIVE_BIT is not specified.
* We choose to ignore the pipeline derivative controls entirely.
  This is consistent with other implementations.
* Also remove assert blocking pipeline construction for subpasses
  other than 0. This works fine.

Test: dEQP-VK.pipeline.derivative.compute.*
Change-Id: Ia03508b33397c60a3de5caf8536f7d75058738f6
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/27828
Presubmit-Ready: Chris Forbes <chrisforbes@google.com>
Tested-by: Chris Forbes <chrisforbes@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>