Use general hardening flag toggle lists

The following parameters are now available:

  * hardeningDisable
    To disable specific hardening flags
  * hardeningEnable
    To enable specific hardening flags

Only the cc-wrapper supports this right now, but these may be reused by
other wrappers, builders or setup hooks.

cc-wrapper supports the following flags:

  * fortify
  * stackprotector
  * pie (disabled by default)
  * pic
  * strictoverflow
  * format
  * relro
  * bindnow

pkgs/tools/misc/sutils/default.nix

@@ -8,7 +8,7 @@ stdenv.mkDerivation rec {
      sha256 = "0xqk42vl82chy458d64fj68a4md4bxaip8n3xw9skxz0a1sgvks8";
    };
 
-   hardening_format = false;
+   hardeningDisable = [ "format" ];
 
    prePatch = ''sed -i "s@/usr/local@$out@" Makefile'';