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/development/libraries/db/db-4.8.nix

@@ -5,5 +5,5 @@ import ./generic.nix (args // rec {
   extraPatches = [ ./clang-4.8.patch ];
   sha256 = "0ampbl2f0hb1nix195kz1syrqqxpmvnvnfvphambj7xjrl3iljg0";
   branch = "4.8";
-  drvArgs = { hardening_format = false; };
+  drvArgs = { hardeningDisable = [ "format" ]; };
 })