[HotColdSplit] Relax requirement that the cold sink block be extractable

Relaxing this requirement creates opportunities to split code dominated
by an EH pad.

Tested on LNT+externals.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@351483 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed