requirements: move the comment about manifestv2 in the module
This is about requirements, so lets put it into the requirements module.
We are about to remove code it was previously attached too.
Differential Revision: https://phab.mercurial-scm.org/D12033
#ifndef HG_COMPAT_H
#define HG_COMPAT_H
#ifdef _WIN32
#ifdef _MSC_VER
#if _MSC_VER < 1900
/* msvc 6.0 has problems */
#define inline __inline
#if defined(_WIN64)
typedef __int64 ssize_t;
typedef unsigned __int64 uintptr_t;
#else
typedef int ssize_t;
typedef unsigned int uintptr_t;
#endif
typedef signed char int8_t;
typedef short int16_t;
typedef long int32_t;
typedef __int64 int64_t;
typedef unsigned char uint8_t;
typedef unsigned short uint16_t;
typedef unsigned long uint32_t;
typedef unsigned __int64 uint64_t;
#else
/* VC++ 14 */
#include <stdint.h>
#if defined(_WIN64)
typedef __int64 ssize_t;
#else
typedef int ssize_t;
#endif
#endif /* _MSC_VER < 1900 */
#else
/* not msvc */
#include <stdint.h>
#endif
#else
/* not windows */
#include <sys/types.h>
#if defined __BEOS__ && !defined __HAIKU__
#include <ByteOrder.h>
#else
#include <arpa/inet.h>
#endif
#include <inttypes.h>
#endif
#if defined __hpux || defined __SUNPRO_C || defined _AIX
#define inline
#endif
#ifdef __linux
#define inline __inline
#endif
#endif