Implement some of the missing LFS64 support.

This gives us:

* <dirent.h>
  struct dirent64
  readdir64, readdir64_r, alphasort64, scandir64

* <fcntl.h>
  creat64, openat64, open64.

* <sys/stat.h>
  struct stat64
  fstat64, fstatat64, lstat64, stat64.

* <sys/statvfs.h>
  struct statvfs64
  statvfs64, fstatvfs64.

* <sys/vfs.h>
  struct statfs64
  statfs64, fstatfs64.

This also removes some of the incorrect #define hacks we've had in the
past (for stat64, for example, which we promised to clean up way back
in bug 8472078).

Bug: 11865851
Bug: 8472078
Change-Id: Ia46443521918519f2dfa64d4621027dfd13ac566
diff --git a/libc/include/fcntl.h b/libc/include/fcntl.h
index b7b91f2..e37e0a7 100644
--- a/libc/include/fcntl.h
+++ b/libc/include/fcntl.h
@@ -42,11 +42,14 @@
 #endif
 
 extern int creat(const char*, mode_t);
+extern int creat64(const char*, mode_t);
 extern int fallocate64(int, int, off64_t, off64_t);
 extern int fallocate(int, int, off_t, off_t);
 extern int fcntl(int, int, ...);
 extern int openat(int, const char*, int, ...);
+extern int openat64(int, const char*, int, ...);
 extern int open(const char*, int, ...);
+extern int open64(const char*, int, ...);
 extern int posix_fallocate64(int, off64_t, off64_t);
 extern int posix_fallocate(int, off_t, off_t);
 extern int unlinkat(int, const char*, int);