Reverting because reverting r200145.
Revert "clang-check: Unittests doesn't requires tools."

This reverts commit r200147.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@200260 91177308-0d34-0410-b5e6-96231b3b80d8
Reverting because reverting r200145.
Revert "check-clang doesn't require neither llvm_src_root nor llvm_obj_root."

This reverts commit r200146.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@200261 91177308-0d34-0410-b5e6-96231b3b80d8