A minor triumph of OAOO for all OBJECT-NOT-<x>-ERROR numbers.

This change:
- Makes it easier to add new errors in compiler/generic/interr.
- Removes the ad-hoc code in checkgen which I had just added to
  map certain type specifiers to internal error numbers.
- Enables collection of a list of type specifiers for which
  checkgen would be more compact if it had a specific error
  number instead of using OBJECT-NOT-TYPE with a symbol.
- Adds a bunch of new error numbers.

On x86-64 the core size is reduced by 300KB.
Change :skipped-on (not :sb-unicode) to #+sb-unicode

The #\ syntax is unparseable.