[patch] Unify handling of PWD

[Rafael Espíndola]

The attached patches centralize the handling of the PWD environment
variable in llvm::sys::fs::current_path().

The only change in behavior I know is that using fake PWD environment
variables in tooling tests doesn't work since we compare the unique id
of PWD with the unique id of '.'.

Cheers,
Rafael
-------------- next part --------------
A non-text attachment was scrubbed...
Name: llvm.patch
Type: application/octet-stream
Size: 718 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20130808/15de31ed/attachment.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: clang.patch
Type: application/octet-stream
Size: 5140 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-commits/attachments/20130808/15de31ed/attachment-0001.obj>