zlib: Declare preprocessor directives at build time

CMakeLists.txt

@@ -70,7 +70,7 @@ IF (WIN32 AND NOT CYGWIN)
 	FILE(GLOB SRC src/*.c src/win32/*.c)
 ENDIF ()
 
-ADD_DEFINITIONS(-D_FILE_OFFSET_BITS=64)
+ADD_DEFINITIONS(-D_FILE_OFFSET_BITS=64 -DNO_VIZ -DSTDC -DNO_GZIP)
 
 # Compile and link libgit2
 ADD_LIBRARY(git2 ${SRC} ${SRC_ZLIB})

deps/zlib/zconf.h

@@ -10,10 +10,6 @@
 
 #include "../../src/common.h"
 
-#define NO_GZIP
-#define STDC
-#define NO_VIZ
-
 /* Jeez, don't complain about non-prototype
  * forms, we didn't write zlib */
 #if defined(_MSC_VER)