r269100 - [VFS] Reconstruct the VFS overlay tree for more accurate lookup

[Bruno Cardoso Lopes via cfe-commits]

> I'm glad to help, but it makes me uneasy to have somebody working on a
> filesystem abstraction that does not have ready access to test and debug
> their changes across the major host platforms that LLVM supports (linux,
> mac, windows). Is there any way you can get access? I don't think that
> windows 10 is critical here; win7 or win8 are fine.

I'm mostly trying to make the crash reproducers to work on Darwin; the
improvements to VFS are in fact side-effects here, not something I'm
working full time on. It would be awesome to have it working on other
platforms out-of-the-box, but I just don't have the bandwidth to do
it. That said, I'm gonna make sure we don't regress on windows, but
unless I have help or get time to setup such machine, I can't
guarantee this improvements are going to be supported on windows.

-- 
Bruno Cardoso Lopes
http://www.brunocardoso.cc