UniformBufferStandardLayout changes the alignment rules for uniform
buffers. This doesn't change SwiftShader's behavior, and is treated as
always enabled for the purposes of validating inputs to SPIRV-Tools.

Bug: b/169604082
Tests: dEQP-VK.ubo.*
Change-Id: I0ec59ceb0bf6cc487f37e292a04e875268c37185
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/49868Tested-by: Sean Risser <srisser@google.com>
Commit-Queue: Sean Risser <srisser@google.com>
Kokoro-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>