Split fs_darwin.h defines into various platform dependent headers.

This completes the final 1/3 of #8857. Changes again by nielx with
style fixes by me.

The one part that I couldn't figure out, and maybe Ingo can chime
in here. If headers/build/host/darwin/sys/stat.h is surrounded in

extern "C" {

}

guards then I get a link error complaining that the functions defined
here are duplicate symbols, once in fs.o and once in function_remapper.o.
For example:

ld: duplicate symbol _futimens in generated/objects/darwin/x86_64/release/build/libroot/libroot_build_function_remapper.a(function_remapper.o) and generated/objects/darwin/x86_64/release/build/libroot/libroot_build.a(fs.o) for architecture x86_64

I'm not sure why that is.

headers/build/host/darwin/fcntl.h

@@ -0,0 +1,34 @@
+#ifndef _HAIKU_BUILD_COMPATIBILITY_DARWIN_FCNTL
+#define _HAIKU_BUILD_COMPATIBILITY_DARWIN_FCNTL
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include_next <fcntl.h>
+#include <sys/time.h>
+
+/*
+ * Magic value that specify the use of the current working directory
+ * to determine the target of relative file paths in the openat() and
+ * similar syscalls.
+ */
+#define AT_FDCWD			-100	/* CWD FD for the *at() functions */
+
+/*
+ * Miscellaneous flags for the *at() syscalls.
+ */
+#define AT_EACCESS			0x100	/* faccessat() */
+#define AT_SYMLINK_NOFOLLOW	0x200	/* fstatat(), fchmodat(), fchownat(),
+									   utimensat() */
+#define AT_SYMLINK_FOLLOW	0x400	/* linkat() */
+#define AT_REMOVEDIR		0x800	/* unlinkat() */
+
+int unlinkat(int fd, const char *path, int flag);
+int futimesat(int fd, const char *path, const struct timeval times[2]);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	// _HAIKU_BUILD_COMPATIBILITY_DARWIN_FCNTL

headers/build/host/darwin/stdio.h

@@ -0,0 +1,17 @@
+#ifndef _HAIKU_BUILD_COMPATIBILITY_DARWIN_STDIO
+#define _HAIKU_BUILD_COMPATIBILITY_DARWIN_STDIO
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include_next <stdio.h>
+
+int renameat(int oldFD, const char* oldPath, int newFD, const char* newPath);
+int symlinkat(const char *oldPath, int fd, const char *newPath);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	// _HAIKU_BUILD_COMPATIBILITY_DARWIN_STDIO

headers/build/host/darwin/sys/stat.h

@@ -1,12 +1,9 @@
 #ifndef _HAIKU_BUILD_COMPATIBILITY_DARWIN_SYS_STAT
 #define _HAIKU_BUILD_COMPATIBILITY_DARWIN_SYS_STAT
 
-
 #include_next <sys/stat.h>
-
 #include <sys/cdefs.h>
 
-
 #ifndef UTIME_NOW
 #	define UTIME_NOW	(-1)
 #	define UTIME_OMIT	(-2)
@@ -28,5 +25,10 @@
 #	endif
 #endif
 
+int fchmodat(int fd, const char* path, mode_t mode, int flag);
+int fstatat(int fd, const char *path, struct stat *st, int flag);
+int mkdirat(int fd, const char *path, mode_t mode);
+int mkfifoat(int fd, const char *path, mode_t mode);
+int mknodat(int fd, const char *name, mode_t mode, dev_t dev);
 
 #endif	/* _HAIKU_BUILD_COMPATIBILITY_DARWIN_SYS_STAT */

headers/build/host/darwin/unistd.h

@@ -0,0 +1,20 @@
+#ifndef _HAIKU_BUILD_COMPATIBILITY_DARWIN_UNISTD
+#define _HAIKU_BUILD_COMPATIBILITY_DARWIN_UNISTD
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include_next <unistd.h>
+
+int faccessat(int fd, const char* path, int accessMode, int flag);
+int fchownat(int fd, const char* path, uid_t owner, gid_t group, int flag);
+ssize_t readlinkat(int fd, const char *path, char *buffer, size_t bufferSize);
+int linkat(int oldFD, const char *oldPath, int newFD, const char *newPath,
+	int flag);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif	// _HAIKU_BUILD_COMPATIBILITY_DARWIN_UNISTD

headers/build/host/freebsd/sys/stat.h

@@ -1,12 +1,9 @@
 #ifndef _HAIKU_BUILD_COMPATIBILITY_FREEBSD_SYS_STAT
 #define _HAIKU_BUILD_COMPATIBILITY_FREEBSD_SYS_STAT
 
-
 #include_next <sys/stat.h>
-
 #include <sys/cdefs.h>
 
-
 #ifndef UTIME_NOW
 #	define UTIME_NOW	(-1)
 #	define UTIME_OMIT	(-2)
@@ -14,7 +11,7 @@
 	__BEGIN_DECLS
 
 	/* assume that futimens() and utimensat() aren't available */
-	int	futimens(int fd, const struct timespec times[2]);
+	int futimens(int fd, const struct timespec times[2]);
 	int utimensat(int fd, const char* path, const struct timespec times[2],
 		int flag);
 
@@ -28,5 +25,4 @@
 #	endif
 #endif
 
-
 #endif	/* _HAIKU_BUILD_COMPATIBILITY_FREEBSD_SYS_STAT */

src/build/libroot/fs.cpp

@@ -31,8 +31,6 @@
 
 #if defined(HAIKU_HOST_PLATFORM_FREEBSD)
 #	include "fs_freebsd.h"
-#elif defined(HAIKU_HOST_PLATFORM_DARWIN)
-#	include "fs_darwin.h"
 #endif
 
 

src/build/libroot/fs_darwin.cpp

@@ -5,8 +5,6 @@
  */
 
 
-#include "fs_darwin.h"
-
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>

src/build/libroot/fs_darwin.h

@@ -1,44 +0,0 @@
-/*
- * Copyright 2005-2011, Ingo Weinhold, [email protected].
- * Copyright 2012, John Scipione, [email protected].
- * Distributed under the terms of the MIT License.
- */
-#ifndef FS_DARWIN_H
-#define FS_DARWIN_H
-
-
-/*
- * Magic value that specify the use of the current working directory
- * to determine the target of relative file paths in the openat() and
- * similar syscalls.
- */
-#define AT_FDCWD			-100	/* CWD FD for the *at() functions */
-
-/*
- * Miscellaneous flags for the *at() syscalls.
- */
-#define AT_EACCESS			0x100	/* faccessat() */
-#define AT_SYMLINK_NOFOLLOW	0x200	/* fstatat(), fchmodat(), fchownat(),
-										utimensat() */
-#define AT_SYMLINK_FOLLOW	0x400	/* linkat() */
-#define AT_REMOVEDIR		0x800	/* unlinkat() */
-
-int faccessat(int fd, const char* path, int accessMode, int flag);
-int fchmodat(int fd, const char* path, mode_t mode, int flag);
-int fchownat(int fd, const char* path, uid_t owner, gid_t group, int flag);
-int fstatat(int fd, const char *path, struct stat *st, int flag);
-int mkdirat(int fd, const char *path, mode_t mode);
-int mkfifoat(int fd, const char *path, mode_t mode);
-int mknodat(int fd, const char *name, mode_t mode, dev_t dev);
-int renameat(int oldFD, const char* oldPath, int newFD, const char* newPath);
-
-ssize_t readlinkat(int fd, const char *path, char *buffer, size_t bufferSize);
-int symlinkat(const char *oldPath, int fd, const char *newPath);
-int unlinkat(int fd, const char *path, int flag);
-int linkat(int oldFD, const char *oldPath, int newFD, const char *newPath,
-	int flag);
-
-int futimesat(int fd, const char *path, const struct timeval times[2]);
-
-
-#endif // FS_DARWIN_H

src/build/libroot/remapped_functions.h

@@ -5,18 +5,10 @@
 #ifndef REMAPPED_FUNCTIONS_H
 #define REMAPPED_FUNCTIONS_H
 
-
-#include <fcntl.h>
-#include <stdio.h>
-#include <unistd.h>
-#include <sys/stat.h>
-
-
 #ifdef __cplusplus
 extern "C" {
 #endif
 
-
 int		_haiku_build_fchmod(int fd, mode_t mode);
 int		_haiku_build_fchmodat(int fd, const char* path, mode_t mode, int flag);
 int		_haiku_build_fstat(int fd, struct stat* st);
@@ -53,7 +45,6 @@ int		_haiku_build_fcntl(int fd, int op, int argument);
 int		_haiku_build_renameat(int fromFD, const char* from, int toFD,
 			const char* to);
 
-
 #ifdef __cplusplus
 } // extern "C"
 #endif