ANSI corpus census: does the gate runner contain every test the corpus defines?

  mkdir -p tmp/ansi-census
  (cd tmp/ansi-test/sandbox && sbcl --dynamic-space-size 4096 --script ../../../test/ansi-census/enum-sbcl.lisp)
      -> tmp/ansi-census/sbcl-tests.txt   (FILE NAME per test SBCL registers)
  python3 test/ansi-census/classify.py <build-x64-linux build log>
      -> counts missing tests by cause; writes tmp/ansi-census/missing.txt

2026-09-23: 1,883 of 19,508 were missing (unexpanded file-local test
macros, unlisted files, load-time generators, guarded deftests, a
read-failing aux file); now 0.
