Revert "DebugInfo: Fix rangesBaseAddress DICompileUnit bitcode serialization/deserialization"

Seeing some curious CFI failures internally - which makes little sense
to me, as I don't think anyone is using this flag (even us,
internally)... so sounds like a bug in my code somewhere (possibly a
latent one that propagating this flag exposed, not sure). Reverting
while I investigate.

This reverts commit c51b45e3.