SimplifyCFG: Omit range checks for switch lookup tables when default is unreachable

They would get optimized away later, but we might as well not emit them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223051 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed