The data layout was only being set right before lowering to machine
code. The optimization passes need accurate data layout info as well.

Bug: b/135691587
Change-Id: Ic1524d57bb6d8d0eb725e33d27e100a6286f1571
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/33309Tested-by: Nicolas Capens <nicolascapens@google.com>
Presubmit-Ready: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Ben Clayton <bclayton@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>