The expression `True xor Current /= Void' incorrectly evaluates to
True when code is frozen, but correctly evaluates to False when code
is melted.  Compiling the generated C code elicits compiler warnings
such as "illegal combination of pointer and integer, op !=".  This
appears to be a precedence problem since fully parenthesized
expressions involving xor produce the correct result when frozen.

Discovered in Release 3.2.2.