Revert "Resubmit "[Support] Expose flattenWindowsCommandLine.""

This reverts commit 65243b6d19143cb7a03f68df0169dcb63e8b4632.

Seems like it's not a flake.  It might have something to do with
the '*' character being in a command line.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334356 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed