Revert "Add llvm::enumerate() to STLExtras."

This reverts commit r282804 as it seems to use some C++ features
that not all compilers support.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@282809 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed