fortify: add bit checking for open(at)?64 functions

This also adds _2-variants for these functions, for extra glorious
checking

Bug: 131861088
Test: mma
Change-Id: I80475ff4bb220c0c47894e9532426f53412f176f
diff --git a/libc/libc.map.txt b/libc/libc.map.txt
index 424c8f3..b12df56 100644
--- a/libc/libc.map.txt
+++ b/libc/libc.map.txt
@@ -1482,6 +1482,8 @@
 
 LIBC_R { # introduced=R
   global:
+    __open64_2;
+    __openat64_2;
     call_once;
     cnd_broadcast;
     cnd_destroy;