[WinEH] Don't forward branches across empty EH pad BBs

For really simple SEH catchpads, we tried to forward the invoke unwind
edge across the empty block.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@252822 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed