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/os-specific/linux/sysdig/default.nix

@@ -16,7 +16,7 @@ stdenv.mkDerivation {
     cmake zlib luajit ncurses perl jsoncpp libb64 openssl curl
   ];
 
-  hardening_pic = false;
+  hardeningDisable = [ "pic" ];
 
   cmakeFlags = [
     "-DUSE_BUNDLED_DEPS=OFF"