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

[Martin Storsjö via llvm-commits]

mstorsjo 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.

FWIW, I’m not sure if the libc++ implementation of these operations have got any extra logic to take care of those corner cases, at least I don’t remember anything extra relating to long paths.

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