Declare getpagesize() - gcc provides it for us.

It is in MinGW's libgcc.a, which appearently is always linked in.

Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>

git-compat-util.h

@@ -508,6 +508,7 @@ int mingw_rename(const char*, const char*);
 static inline int fsync(int fd) { return 0; }
 static inline int getppid(void) { return 1; }
 static inline void sync(void) {}
+extern int getpagesize(void);	/* defined in MinGW's libgcc.a */
 
 extern void quote_argv(const char **dst, const char **src);
 extern const char *parse_interpreter(const char *cmd);