A few things were buggy in the last provoking vertex cl:
- There were 2 separate loops for rasterizationState extensions.
  Correctly combined them into a single loop.
- There was a missing break statement in vkCreateDevice
- There was a missing case in vkGetPhysicalDeviceFeatures2

Bug: angleproject:3677, angleproject:3430
Change-Id: Id4a16168933fc8c440b7339851a39e8cc4683491
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/37688
Presubmit-Ready: Alexis Hétu <sugoi@google.com>
Reviewed-by: Antonio Maiorano <amaiorano@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Tested-by: Alexis Hétu <sugoi@google.com>