Revert r111922, "MapValue support for MDNodes. This is similar to r109117,
except ...", it is causing *massive* performance regressions when building Clang
with itself (-O3 -g).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112158 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed