Add getBitCastOrAddrSpaceCast

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196637 91177308-0d34-0410-b5e6-96231b3b80d8
Fix assert with copy from global through addrspacecast

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@196638 91177308-0d34-0410-b5e6-96231b3b80d8