[PM/AA] Hoist the AA counter pass into a header to match the analysis

[PM/AA] Hoist the AA counter pass into a header to match the analysis
pattern.

Also hoist the creation routine out of the generic header and into the
pass header now that we have one.

I've worked to not make any changes, even formatting ones here. I'll
clean up the formatting and other things in a follow-up patch now that
the code is in the right place.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@245004 91177308-0d34-0410-b5e6-96231b3b80d8