Plea for minimal tagbits

I'd like to see --use-minimal-tagbits being default, and the other alternative actually removed. Rationale: - per Kyle's study, performance is equivalent - we have to settle on one of the options for code-freezing time in order to ensure proper testing on all architectures - not munging pointers is infinitely better because: * it removes the need for DATA_SEG_BITS which, basically, sucks * it makes purify-like memory leak detection possible - it gives us 31bits integers and 30bits characters, and *ensures* that we have them as soon as version>=21.0 - code in lisp.h becomes cleaner (the less #ifdefs, the better) What do you think ? OG.