This is vanilla zlib-1.3.1 imported over the existing zlib/ dir with:
* README adjusted to add the GCC note at the top;
* GCC's ChangeLog merged with the upstream one, as before;
* Deleted upstream Makefile as has been done before (we use an autoconf-
generated one)
* Import zlib 1.2.11.
* configure: Regenerate.
Changes in 1.2.11 (15 Jan 2017)
- Fix deflate stored bug when pulling last block from window
- Permit immediate deflateParams changes before any deflate input
From-SVN: r244762