31.0.91; flymake-test failure on 32-bit Solaris sparc

This follows up on bug#81465 "31.0.91; ‘make check’ failures on Solaris 
10 sparc 32-bit" and I am splitting this issue off into a separate bug 
report.

Here is the log of the failure:

   GEN      lisp/progmodes/flymake-tests.log
Running 10 tests (2026-07-23 14:43:27-0700, selector `(not (or (tag 
:expensive-test) (tag :unstable) (tag :nativecomp)))')
   skipped   1/10  different-diagnostic-types (0.250526 sec)
    passed   2/10  dummy-backends (1.019288 sec)
    passed   3/10  eob-region-and-trailing-newline (0.001679 sec)
Test foreign-diagnostics backtrace:
   signal(ert-test-failed (((should (eq 'flymake-note (face-at-point)))
   ert-fail(((should (eq 'flymake-note (face-at-point))) :form (eq flym
   #f(compiled-function () #<bytecode 0x17b82ef6>)()
   flymake-tests--call-with-fixture(#f(compiled-function () #<bytecode
   #f(compiled-function () #<bytecode 0x1c41cc86>)()
   flymake-tests--call-with-fixture(#f(compiled-function () #<bytecode
   #f(compiled-function () #<bytecode -0x33384c5>)()
   #f(compiled-function () #<bytecode -0x63d2553>)()
   handler-bind-1(#f(compiled-function () #<bytecode -0x63d2553>) (t) #
   ert--run-test-internal(#s(ert--test-execution-info :test #s(ert-test
   ert-run-test(#s(ert-test :name foreign-diagnostics :documentation "T
   ert-run-or-rerun-test(#s(ert--stats :selector ... :tests ... :test-m
   ert-run-tests((not (or (tag :expensive-test) (tag :unstable) (tag :n
   ert-run-tests-batch((not (or (tag :expensive-test) (tag :unstable) (
   ert-run-tests-batch-and-exit((not (or (tag :expensive-test) (tag :un
   eval((ert-run-tests-batch-and-exit '(not (or (tag :expensive-test) (
   command-line-1(("-L" ":../../emacs-31.0.91/test" "-l" "ert" "--eval"
   command-line()
   normal-top-level()
Test foreign-diagnostics condition:
     (ert-test-failed
      ((should (eq 'flymake-note (face-at-point))) :form
       (eq flymake-note flymake-error) :value nil))
    FAILED   4/10  foreign-diagnostics (3.201877 sec) at 
../../emacs-31.0.91/test/lisp/progmodes/flymake-tests.el:186
    passed   5/10  included-c-header-files (2.200565 sec)
    passed   6/10  perl-backend (1.063338 sec)
    passed   7/10  recurrent-backend (1.014605 sec)
    passed   8/10  ruby-backend (1.124172 sec)
    passed   9/10  warning-predicate-function-gcc (1.096327 sec)
    passed  10/10  warning-predicate-rx-gcc (1.095108 sec)

Ran 10 tests, 8 results as expected, 1 unexpected, 1 skipped (2026-07-23 
14:43:40-0700, 13.075516 sec)

1 unexpected results:
    FAILED  foreign-diagnostics

1 skipped results:
   SKIPPED  different-diagnostic-types

gmake[4]: *** [lisp/progmodes/flymake-tests.log] Error 1