Auto merge of #2837 - devnexen:linux_ptr_auth_followup, r=JohnTitor

linux arm64 pointer, prctl  auth control follow-up.

Author: bors

src/unix/linux_like/linux/gnu/b64/aarch64/mod.rs

@@ -576,10 +576,20 @@ pub const HWCAP_PACG: ::c_ulong = 1 << 31;
 //pub const HWCAP2_MTE: ::c_ulong = 1 << 18;
 
 // linux/prctl.h
+pub const PR_PAC_RESET_KEYS: ::c_int = 54;
 pub const PR_SET_TAGGED_ADDR_CTRL: ::c_int = 55;
 pub const PR_GET_TAGGED_ADDR_CTRL: ::c_int = 56;
+pub const PR_PAC_SET_ENABLED_KEYS: ::c_int = 60;
+pub const PR_PAC_GET_ENABLED_KEYS: ::c_int = 61;
+
 pub const PR_TAGGED_ADDR_ENABLE: ::c_ulong = 1;
 
+pub const PR_PAC_APIAKEY: ::c_ulong = 1 << 0;
+pub const PR_PAC_APIBKEY: ::c_ulong = 1 << 1;
+pub const PR_PAC_APDAKEY: ::c_ulong = 1 << 2;
+pub const PR_PAC_APDBKEY: ::c_ulong = 1 << 3;
+pub const PR_PAC_APGAKEY: ::c_ulong = 1 << 4;
+
 // Syscall table
 pub const SYS_io_setup: ::c_long = 0;
 pub const SYS_io_destroy: ::c_long = 1;