Revert "Switch external cvtres.exe for llvm's own resource library."

This reverts commit 600d52c278e123dd08bee24c1f00932b55add8de.

This patch still seems to break CrWinClangLLD, reverting until I can
find root problem.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@307189 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed