Add posix_fadvise(3).

(cherry-pick of 00008263782e484020420c606f7d145fe7d0a4d8.)

Bug: 12449798
Change-Id: I07cbf3f670a0d1304b68148325a774f266b5c433
diff --git a/libc/arch-arm64/syscalls/__fadvise64.S b/libc/arch-arm64/syscalls/__fadvise64.S
new file mode 100644
index 0000000..695d094
--- /dev/null
+++ b/libc/arch-arm64/syscalls/__fadvise64.S
@@ -0,0 +1,15 @@
+/* Generated by gensyscalls.py. Do not edit. */
+
+#include <private/bionic_asm.h>
+
+ENTRY(__fadvise64)
+    mov     x8, __NR_fadvise64
+    svc     #0
+
+    cmn     x0, #(MAX_ERRNO + 1)
+    cneg    x0, x0, hi
+    b.hi    __set_errno_internal
+
+    ret
+END(__fadvise64)
+.hidden __fadvise64