Remove typedef of a pointer type used in a gep to simplify migration of geps...

Remove typedef of a pointer type used in a gep to simplify migration of geps to a typeless-pointer future.

I'd modify my migration tool to account for this, but this is the only
instance of a typedef'd pointer type to a gep I found in the whole test
suite, so it didn't seem worthwhile.

llvm-svn: 228970