[llvm] [llvm][Support][Windows] Avoid crash calling remove_directories() (PR #118677)

[Saleem Abdulrasool via llvm-commits]

compnerd wrote:

Manually performing the DFS and doing the removal would require that we properly handle long paths and that we handle some of the permission work (e.g. IIRC backup semantics may sometimes be required to remove the file). Even `del` in `cmd` has trouble with long paths, so we should be careful to not re-invent the removal logic if not absolutely necessary. I expect that @rnk would also have some thoughts here.

https://github.com/llvm/llvm-project/pull/118677