Don't accidentally fail to eat whitespace after the token NIL.
Improve previous reader fix.
Speed up sb-unicode:unicode<

Mainly by avoiding frivolous consing.
Remove UNICODE1_ from unicode-1 character name database.

The way it's used, there's no chance of collision with normal Unicode
names, the only visible change is that what previously was
#\UNICODE1_START_OF_HEADING now is #\START_OF_HEADING.
Ensure that all interned symbols have a precomputed hash.
Make cold-stderr work even earlier so that strings can be printed ASAP.