Arch Linux

See https://github.com/madler/zlib/pull/229

The presence of this header currently results in sigil FTBFS:

In file included from /usr/include/python3.6m/Python.h:39,
from /build/sigil/src/Sigil-0.9.9/src/Misc/EmbeddedPython.h:26,
from /build/sigil/src/Sigil-0.9.9/src/main.cpp:22:
/usr/include/minizip/crypt.h:35:53: error: ‘z_crc_t’ does not name a type
static int decrypt_byte(unsigned long* pkeys, const z_crc_t* pcrc_32_tab)
^~~~~~~
/usr/include/minizip/crypt.h:48:51: error: ‘z_crc_t’ does not name a type
static int update_keys(unsigned long* pkeys,const z_crc_t* pcrc_32_tab,int c)
^~~~~~~
/usr/include/minizip/crypt.h:65:69: error: ‘z_crc_t’ does not name a type
static void init_keys(const char* passwd,unsigned long* pkeys,const z_crc_t* pcrc_32_tab)
^~~~~~~
This seems to be triggered by https://github.com/python/cpython/commit/8e230e1eb3d38ad557b5dc5c31166afa35c01ff3#diff-91e2f1afdf2d483697c7101d613725b3 which means python 3.6.5 now tries including crypt.h, and since sigil uses minizip, it gets looked for first.