Panic on loading foreign declarations with recursive cryptol implementations

[qsctr]

Forgot to change this when adding support for cryptol implementations of foreign functions

foreign f : Bit -> Bit
f x = ~ g x

foreign g : Bit -> Bit
g x = ~ f x

Cryptol> :l test.cry
Loading module Cryptol
Loading module Main
cryptol: You have encountered a bug in Cryptol's implementation.
*** Please create an issue at https://github.com/GaloisInc/cryptol/issues

%< --------------------------------------------------- 
  Revision:  7f7ec412eaa876989bdaa41e08a683dc19045f48
  Branch:    foreign-cryptol-def (uncommited files present)
  Location:  [Eval] Unexpected foreign declaration in recursive group
  Message:   (at test.cry:2:1--2:2, Main::f)
CallStack (from HasCallStack):
  panic, called at src/Cryptol/Utils/Panic.hs:21:9 in cryptol-3.0.0.99-inplace:Cryptol.Utils.Panic
  panic, called at src/Cryptol/Backend/Monad.hs:410:17 in cryptol-3.0.0.99-inplace:Cryptol.Backend.Monad
  evalPanic, called at src/Cryptol/Eval.hs:437:21 in cryptol-3.0.0.99-inplace:Cryptol.Eval
%< ---------------------------------------------------