This will halve the size of the input and output arrays used to communicate with the shader.
This is likely to have been already cleaned up by llvm, but better to not make the mess to start with.

Bug: b/125909515
Change-Id: I960647f808b722fe8ad38ff716df1461e1eae4ef
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/33788Tested-by: Chris Forbes <chrisforbes@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>