UTF-8 locales on BSDs do not support collation correctly

["Jun T." <takimoto-j@xxxxxxxxxxxxxxxxx>]

After the commit:

commit 0e33ebc6514c8719513f3f20161274f6af2caffc
Author: Mikael Magnusson <mikachu@xxxxxxxxx>
Date:   Tue Jan 24 12:01:57 2017 +0100

    posted: Make D07 recognize more spellings of pl_PL.UTF-8

diff --git a/Test/D07multibyte.ztst b/Test/D07multibyte.ztst
(snip) 
-  if [[ -n ${$(locale -a 2>/dev/null)[(R)pl_PL.utf8]} ]]; then
+  if [[ -n ${$(locale -a 2>/dev/null)[(R)pl_PL.(utf8|UTF-8)]} ]]; then


the test D07multibyte.ztst fails on macOS and freeBSD.
On these OSs (and maybe on other BSDs), the locale pl_PL.UTF-8 exists
but it does not support collation correctly (it just uses ASCII collation).

Are there any OS which uses UTF-8 (instead of utf8) for locale name
and supports the collation correctly?