SCEVCodegen should not run createIndVarSimplifyPass

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@179018 91177308-0d34-0410-b5e6-96231b3b80d8
IndependentBlocks: translate out of SSA all uses escaping the region

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@179019 91177308-0d34-0410-b5e6-96231b3b80d8