Temporarily revert r191792 as it is causing some LTO debug failures
on platforms with relocations in debug info and also temporarily
revert r191800 due to conflicts with the revert of r191792.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191967 91177308-0d34-0410-b5e6-96231b3b80d8
Add lto_codegen_add_dso_symbol to the export list.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@191970 91177308-0d34-0410-b5e6-96231b3b80d8