This extension allows subgroup operations to use 8-bit, 16-bit, and
64-bit integers as well as 16-bit floating point types if the
implementation supports those types. So no work is required other
than enabling the extension.

Bug: b/169606946
Tests: dEQP-VK.subgroups.arithmetic.*
Change-Id: I824ad65a1c9d5f9fb98bc5769f97920de5815d0f
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/49448Tested-by: Sean Risser <srisser@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Kokoro-Result: kokoro <noreply+kokoro@google.com>