1.0.0.18:

1.0.0.18:
        Add an xref facility, exported from sb-introspect.

        * Support who-calls/macroexpands/binds/sets/references, with
          full source path information for extra Slime-goodness.
        * Only causes relatively small amounts of compilation slowdown
          or fasl bloat, so enable it by default (unless (= SPEED 3)).
        * Does not handle: expanded compiler-macros, code in macrolet
          definition bodies, toplevel code
        * Xref data is currently stored in a new simple-fun slot (the
          FUN_RAW_ADDR mess has been cleaned up a little), in reverse
          format (that is, we store who-is-called rather than who-calls).
        * sb-introspect gets access to the simple-funs through the
          infodb, so each lookup requires looping through the whole
          db. This is snappy enough on my machine even with lots of
          code loaded, but some other storage strategy might be
          worth looking at later.