Much to my surprise, '-disable-llvm-optzns' which I thought was the
magical flag I wanted to get at the raw LLVM IR coming out of Clang
deosn't do that. It still runs some passes over the IR. I don't want
that, I really want the *raw* IR coming out of Clang and I strongly
suspect everyone else using it is in the same camp.
I've not talked to anyone debugging Clang and LLVM interactions that
needed these different flags so I'd like to remove the less widely known
one (I think) and consolidate on a simple, strong model for the one flag
This is part of simplifying how Clang drives LLVM to make it cleaner to
wire up to the new pass manager.