This reverts commit 4ea1a647ff0973c683dd71fec77e6fe7f6dfd2ca. This breaks on Darwin which tries to export these symbols ebb258d3b0/clang/lib/Driver/ToolChains/Darwin.cpp (L1363) I'll try to reland which that removed and approval from Apple folks.
ebb258d3b0/clang/lib/Driver/ToolChains/Darwin.cpp (L1363)