Paul, a typo was introduced, which causes multiple tests to fail.
Please have a look at sv62173_fix_typo.diff.

The patch contains the following changes

-my $arflags = 'rv';
+my $arflags = '-rv';
+if ($^O eq 'aix') {
+    $arflags = "-Xany -rv";
+}

That reason for the first part of the patch, specifically

-my $arflags = 'rv';
+my $arflags = '-rv'

is the following

The test has the following piece of code

$_ = `$ar U$arflags libxx.a a1.o $redir`;
if ($? == 0) {
    $arflags = 'Urv';
    $arvar = "$arvar ARFLAGS=$arflags";
}

This piece of code causes $arvar contain $arflags.
This happens only when ar supports -U. This is relatively new version of gnu ar.
Other systems (not only aix) won't have ar support -U and $arvar on those systems does not contain $arflags. The default value of ARFLAGS builtin in make was change from 'rv' to -rv' in 0e020bbc24d89592e9ea15f9e8b887a71692eedf. This makes the test fail on any system where ar does not support -U.

The other part of the patch, specifically

+if ($^O eq 'aix') {
+    $arflags = "-Xany -rv";
+}

is indeed aix specific. I originally proposed to use an env var OBJECT_MODE and keep arflags intact on aix (see sv 59096). But that robs the user of the ability to override the value.
However, i'd call this change trivial.

> I have quite a few of similar issues with the test suite on MS-Windows, but I never thought I should make changes non-trivial to the test suite to make those pseudo-failures pass.  Instead, I eyeball the test diffs to determine whether the issue is real or not.

i once had to make a change which affected windows (sv 60774). Once i was able to build make, i wanted to check that the test suite passes. It did not. i am not familiar with windows. i'd definitely appreciate if the test suite passed. Similarly, if you ever have to make a change on sun or aix, etc, you'll appreciate if the test suite passes.

features/archives tests fail on aix, because make passes ARFLAGS='-Xany -rv', the test expects ARFLAGS='rv'.

Clearing work...
Making work dirs...

features/archives ....................................... FAILED (5/12 passed)

7 Tests in 1 Category Failed (See .diff* files in work dir for details) :-(

$ cat work/features/archives.diff
archives.diff     archives.diff.10  archives.diff.4   archives.diff.6
archives.diff.1   archives.diff.2   archives.diff.5
$ cat work/features/archives.diff
*** work/features/archives.base Sat Mar 12 12:12:52 2022
--- work/features/archives.log  Sat Mar 12 12:12:52 2022
***************
*** 1,3 ****
! ar rv libxx.a a1.o
  ar: creating an archive file libxx.a
  a - a1.o
--- 1,3 ----
! ar -Xany -rv libxx.a a1.o
  ar: creating an archive file libxx.a
  a - a1.o

Similary features/archives tests fail on sun, because make passes ARFLAGS='-rv, the tests expect ARFLAGS='rv'.

features/archives ....................................... FAILED (5/12 passed)

7 Tests in 1 Category Failed (See .diff* files in work dir for details) :-(

$ cat work/features/archives.diff
*** work/features/archives.base Sat Mar 12 12:18:35 2022
--- work/features/archives.log  Sat Mar 12 12:18:35 2022
***************
*** 1,4 ****
! ar rv libxx.a a1.o
  ar: creating libxx.a
  ar: writing libxx.a
  a - a1.o
--- 1,4 ----
! ar -rv libxx.a a1.o
  ar: creating libxx.a
  ar: writing libxx.a