Add support for BSD format Archive map symbols (aka the table of contents
from a __.SYMDEF or "__.SYMDEF SORTED" archive member).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212568 91177308-0d34-0410-b5e6-96231b3b80d8
DominanceInfo is strongly preferred over RegionInfo

This is and always was strong community consensus. Make this clear in the header
in case newcomers may not be aware.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212570 91177308-0d34-0410-b5e6-96231b3b80d8