Fix borderline incorrect expansion of a globaldb iterator macro.

The simple form of LOOP is not supposed to contain any atoms.
Clisp rejects that and it's probably right to do so.
Fix style-warning in DEF-IR1-TRANSLATOR RETURN-FROM.

An IGNORE was getting injected not in direct relation to its binding,
but it didn't matter because the macroexpansion declares some args
ignorable anyway, for better or for worse.
Make raw slots of type SB!VM:WORD usable earlier in cold-init.