How to define custom hardened gcc?

[kiasoc5]

Dear Guixers,

I want to build gcc with --enable-default-ssp and --enable-default-pie, and 
have all packages built with gcc to be built by my hardened gcc, since Guix 
does not have a hardened toolchain yet.

How might I define a custom gcc that I can recompile all my packages with? I 
have this in mind but am not sure if it works.

(define-public gcc
  (package
    (inherit gcc)
    (arguments
     (substitute-keyword-arguments (package-arguments gcc)
     ((#:configure-flags flags
       `(append (list "--enable-default-ssp" "--enable-default-pie")
            ,flags)))))))

Thanks,
kiasoc5