Use a SmallPtrSet to dedup successors in EmitSjLjDispatchBlock.

The test case ARM/2011-05-04-MultipleLandingPadSuccs.ll was creating
duplicate successor list entries.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162222 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed