Bash has a very convenient feature that is called process substitution
(e.g. `diff -u <(seq 0 10) <(seq 1 11)`). To make this work, Bash
requires the `/dev/fd` symlink to exist, and Cygwin therefore creates
this symlink (together with the `stdin`, `stdout` and `stderr` ones)
upon start-up.
This strategy is incompatible with the idea of providing a subset of
Cygwin in a `.zip` file (because there is no standard way to represent
symlinks in `.zip` files, and besides, older Windows versions would
potentially lack support for them anyway).
That type of `.zip` file is what Git for Windows wants to use, though,
bundling a minimal subset for third-party applications in MinGit (see
https://github.com/git-for-windows/git/wiki/MinGit for details).
Let's side-step this problem completely by creating those symlinks
implicitly, similar to the way `/dev/` is populated with special
devices.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>