Initial basic implementation of PipelineLayout. The information
stored in the PipelineLayout will be used, among other things,
to properly bind descriptor sets affected by a dynamic offset.

Bug b/118386749

Change-Id: I05fa6f9c7740cf79a802a5276e2d88f6e6e4ebe7
Reviewed-on: https://swiftshader-review.googlesource.com/c/24948Tested-by: Alexis Hétu <sugoi@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Corentin Wallez <cwallez@google.com>
Reviewed-by: Chris Forbes <chrisforbes@google.com>