[opaque pointer type] gep API migration

This concludes the GetElementPtrInst::Create migration, thus marking the
beginning of the IRBuilder::CreateGEP* migration to come.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@232280 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed