regcomp.c: Rmv inaccurate and tangential comment

This comment contained inaccuracies and referred to behavior that has
been removed from the core for years.  isPRINT() is sufficiently
documented elsewhere to not need to have its use justified here.

I considered moving part of it to perlebcdic, but it's not generally
true: it's not true for one of Perl's supported EBCDIC code pages, for
example.

diff --git a/regcomp.c b/regcomp.c
index baf7e32..0239361 100644 (file)
--- a/regcomp.c
+++ b/regcomp.c
@@ -16124,19 +16124,6 @@ S_put_byte(pTHX_ SV *sv, int c)
 {
     PERL_ARGS_ASSERT_PUT_BYTE;
 
-    /* Our definition of isPRINT() ignores locales, so only bytes that are
-       not part of UTF-8 are considered printable. I assume that the same
-       holds for UTF-EBCDIC.
-       Also, code point 255 is not printable in either (it's E0 in EBCDIC,
-       which Wikipedia says:
-
-       EO, or Eight Ones, is an 8-bit EBCDIC character code represented as all
-       ones (binary 1111 1111, hexadecimal FF). It is similar, but not
-       identical, to the ASCII delete (DEL) or rubout control character. ...
-       it is typically mapped to hexadecimal code 9F, in order to provide a
-       unique character mapping in both directions)
-
-       So the old condition can be simplified to !isPRINT(c)  */
     if (!isPRINT(c)) {
         switch (c) {
             case '\r': Perl_sv_catpvf(aTHX_ sv, "\\r"); break;