Add posix_fadvise(3).

Bug: 12449798
Change-Id: I07cbf3f670a0d1304b68148325a774f266b5c433
diff --git a/libc/include/fcntl.h b/libc/include/fcntl.h
index 4450bb6..8f89afb 100644
--- a/libc/include/fcntl.h
+++ b/libc/include/fcntl.h
@@ -72,6 +72,8 @@
 extern int openat64(int, const char*, int, ...);
 extern int open(const char*, int, ...);
 extern int open64(const char*, int, ...);
+extern int posix_fadvise64(int, off64_t, off64_t, int);
+extern int posix_fadvise(int, off_t, off_t, int);
 extern int posix_fallocate64(int, off64_t, off64_t);
 extern int posix_fallocate(int, off_t, off_t);
 extern ssize_t splice(int, off64_t*, int, off64_t*, size_t, unsigned int);