- Proper support for calculating offsets in explicit-layout storage
classes (push constant, uniform, and storage buffer) according to the
Offset, ArrayStride and MatrixStride decorations.
- Plumb a block of push constant data throughout the pipeline
- Implement push constant update commands

Bug: b/128690261
Bug: b/128872954
Test: dEQP-VK.*push_constant*
Test: dEQP-VK.glsl.*
Test: dEQP-VK.spirv_assembly.*
Change-Id: I7d5a66ac4aafd6b637b4693eb6ce96a327b4904e
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/27528Tested-by: Chris Forbes <chrisforbes@google.com>
Presubmit-Ready: Chris Forbes <chrisforbes@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>