SplitCriticalEdge can sometimes split the edge from an invoke to a landing

SplitCriticalEdge can sometimes split the edge from an invoke to a landing
pad, separating the exception and selector calls from the new lpad.  Teaching
it not to do that, or to properly adjust the CFG afterwards, is out of
scope because it would require the other edges to the landing pad to be split
as well (effectively).  Instead, just recover from the most likely cases
during inlining.  The best long-term solution is to change the exception
representation and commit to either requiring or not requiring the more
complex edge-splitting logic;  this is just a shorter-term hack.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132799 91177308-0d34-0410-b5e6-96231b3b80d8