Remove unused SCEV functions

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193097 91177308-0d34-0410-b5e6-96231b3b80d8
Fix creating bitcasts between address spaces in SCEV.

The test before wasn't successfully testing this
since it was missing the datalayout piece to change
the size of the second address space.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193102 91177308-0d34-0410-b5e6-96231b3b80d8
Teach SimplifyCFG about address spaces

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193104 91177308-0d34-0410-b5e6-96231b3b80d8