[EH] Handle non-Function personalities like unknown personalities

[EH] Handle non-Function personalities like unknown personalities

Also delete and simplify a lot of MachineModuleInfo code that used to be
needed to handle personalities on landingpads.  Now that the personality
is on the LLVM Function, we no longer need to track it this way on MMI.
Certainly it should not live on LandingPadInfo.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246478 91177308-0d34-0410-b5e6-96231b3b80d8