I believe these additional failures are due to -fsanitize=undefined
-fno-sanitize-recover=all.

SUMMARY OF TEST RESULTS
-----------------------
Files examined: 267
Ran 3850 tests, 7 failed to run, 3763 results as expected, 1
unexpected, 86 skipped
1 files did not contain any tests:
  src/emacs-module-tests.log
1 files did not finish:
  lisp/international/ccl-tests.log
1 files contained unexpected results:
  lisp/cedet/srecode-utest-template.log
Makefile:319: recipe for target 'check-doit' failed
make[2]: *** [check-doit] Error 2
make[2]: Leaving directory '/home/jwalton/Build-Scripts/emacs-27.1/test'
Makefile:289: recipe for target 'check' failed
make[1]: *** [check] Error 2
make[1]: Leaving directory '/home/jwalton/Build-Scripts/emacs-27.1/test'
Makefile:959: recipe for target 'check' failed
make: *** [check] Error 2

Here's a typical failure:

$ cat emacs-27.1/test/lisp/international/ccl-tests.log
Running 7 tests (2020-08-01 16:28:12-0400, selector `(not (or (tag
:expensive-test) (tag :unstable)))')
   passed  1/7  ccl-compile-midi (0.000181 sec)
   passed  2/7  ccl-compile-pgg (0.000093 sec)
   passed  3/7  ccl-dump-midi (0.005956 sec)
   passed  4/7  ccl-dump-pgg (0.000111 sec)
Package pgg-def is deprecated
Package pgg-parse is deprecated
Package pgg is deprecated
ccl.c:1146:29: runtime error: left shift of 1246883553 by 1 places
cannot be represented in type 'int'