SAWScript thinks terms are equal when they're not

[brianhuffman]

Here's an example:

   ___  __ _ _ _ _
  / __|/ _' | | | |
  \__ \ (_| | | | |
  |___/\__,_|\_,_/ version 0.1.1-dev (5137b8a)

Loading module Cryptol
sawscript> let {{ foo = 0x4 }}
sawscript> let {{ bar = 0x7 }}
sawscript> rewrite (add_prelude_eqs ["eq_refl"] (cryptol_ss())) {{ foo == bar }}
Prelude.True

Basically, the rewriter thinks that foo == bar matches the reflexivity rule for equality, because a term equality comparison between foo and bar returns True.