Reverting r263474; it turns out there are uses of the public interface, but...

Reverting r263474; it turns out there are uses of the public interface, but MSVC wasn't caring about them.

http://lab.llvm.org:8080/green//job/clang-stage1-cmake-RA-incremental_build/21475/consoleFull#-45876453249ba4694-19c4-4d7e-bec5-911270d8a58c
http://lab.llvm.org:8011/builders/llvm-clang-lld-x86_64-scei-ps4-ubuntu-fast/builds/8879

llvm-svn: 263475