[PATCH] Add xchdir to libsupport.

[Florian Weimer]

* Alexandra Hájková via Libc-alpha:

>  support/xchdir.c | 27 +++++++++++++++++++++++++++
>  1 file changed, 27 insertions(+)
>  create mode 100644 support/xchdir.c

You need to update support/Makefile and one of the header files
(presumably support/xunistd.h) and include that in the implementation
file.