HotColdSplit: fix invalid SSA due to outlining

The test used to fail with an invalid phi node: the two predecessors were outlined
and the SSA representation was left invalid. The patch adds the exit block to the
cold region.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@342277 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed