Remove lto_codegen_set_whole_program_optimization. It is a work in progress,
so we don't want it to show up in the stable 3.1 interface.

While at it, add a comment about why LTOCodeGenerator manually creates the
internalize pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154807 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed