[PM] Simplify the interface exposed for IR printing passes.

Nothing was using the ability of the pass to delete the raw_ostream it
printed to, and nothing was trying to pass it a pointer to the
raw_ostream. Also, the function variant had a different order of
arguments from all of the others which was just really confusing. Now
the interface accepts a reference, doesn't offer to delete it, and uses
a consistent order. The implementation of the printing passes haven't
been updated with this simplification, this is just the API switch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@199044 91177308-0d34-0410-b5e6-96231b3b80d8