Support for these features fell out of doing the indirect support
properly. They are optional in the Vulkan spec because of certain
hardware that can't source the base instance indirectly, or would
require the multi draw to be unrolled in the command buffer. We
have neither constraint.

Bug: b/118619338
Test: dEQP-VK.draw.*
Change-Id: I92291acc06a3abc5f25ea2a2eea18634b3035a01
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/27889Tested-by: Chris Forbes <chrisforbes@google.com>
Presubmit-Ready: Chris Forbes <chrisforbes@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>