In commit
571d5cf7467f1af9ff1e6d751f49ac47e4f88380, I forgot that this
is dual-lifed and may be used on early Perls. This commit allows that,
but it will fail if such a Perl were to be used on an EBCDIC platform.
$x = join '', map {chr $_} (0..1023);
is($x, ${thaw freeze \$x});
-# Char in the range 127-255 (probably) in utf8
-$x = chr(utf8::unicode_to_native(175)) . chr (256);
+# Char in the range 127-255 (probably) in utf8. This just won't work for
+# EBCDIC for early Perls.
+$x = ($] lt 5.007_003) ? chr(175) : chr(utf8::unicode_to_native(175))
+ . chr (256);
chop $x;
is($x, ${thaw freeze \$x});