Turns out you can download a MS version of this header from:
https://github.com/mattn/gntp-send/blob/master/include/msinttypes/stdint.h
A portable one can be found here:
http://www.azillionmonkeys.com/qed/pstdint.h
Thanks to the Software Ramblings blog.
NB: The Public Domain version of the header, mentioned by Michael Burr in a comment, can be find as an archived copy here. An updated version can be found in the Android source tree for libusb_aah.