Remove qr/\p{_Case_Ignorable}/

This property is no longer used in the core, nor in cpan, and is marked
as for core use only, not necessarily stable.  I have kept it around
because it was work to remove it, but now the revamping of the property
lookup scheme was causing failures with it, when compiling on early
Unicode releases.  That could be fixed with extra work, but simply
removing it also fixes the problem and avoids future maintenance
costs.

1 files changed, 0 insertions, 50 deletions

diff --git a/lib/unicore/mktables b/lib/unicore/mktables
index e531b44066..1b295a4b35 100644
--- a/lib/unicore/mktables
+++ b/lib/unicore/mktables
@@ -14617,56 +14617,6 @@ sub compile_perl() {
         $Lower->set_caseless_equivalent($cased);
     }
 
-    # Similarly, set up our own Case_Ignorable property if this Unicode
-    # version doesn't have it.  From Unicode 5.1: Definition D121: A character
-    # C is defined to be case-ignorable if C has the value MidLetter or the
-    # value MidNumLet for the Word_Break property or its General_Category is
-    # one of Nonspacing_Mark (Mn), Enclosing_Mark (Me), Format (Cf),
-    # Modifier_Letter (Lm), or Modifier_Symbol (Sk).
-
-    # Perl has long had an internal-only alias for this property; grandfather
-    # it in to the pod, but discourage its use.
-    my $perl_case_ignorable = $perl->add_match_table('_Case_Ignorable',
-                                                     Re_Pod_Entry => 1,
-                                                     Fate => $INTERNAL_ONLY,
-                                                     Status => $DISCOURAGED);
-    my $case_ignorable = property_ref('Case_Ignorable');
-    if (defined $case_ignorable && ! $case_ignorable->is_empty) {
-        $perl_case_ignorable->set_equivalent_to($case_ignorable->table('Y'),
-                                                                Related => 1);
-    }
-    else {
-
-        $perl_case_ignorable->initialize($gc->table('Mn') + $gc->table('Lm'));
-
-        # The following three properties are not in early releases
-        $perl_case_ignorable += $gc->table('Me') if defined $gc->table('Me');
-        $perl_case_ignorable += $gc->table('Cf') if defined $gc->table('Cf');
-        $perl_case_ignorable += $gc->table('Sk') if defined $gc->table('Sk');
-
-        # For versions 4.1 - 5.0, there is no MidNumLet property, and
-        # correspondingly the case-ignorable definition lacks that one.  For
-        # 4.0, it appears that it was meant to be the same definition, but was
-        # inadvertently omitted from the standard's text, so add it if the
-        # property actually is there
-        my $wb = property_ref('Word_Break');
-        if (defined $wb) {
-            my $midlet = $wb->table('MidLetter');
-            $perl_case_ignorable += $midlet if defined $midlet;
-            my $midnumlet = $wb->table('MidNumLet');
-            $perl_case_ignorable += $midnumlet if defined $midnumlet;
-        }
-        else {
-
-            # In earlier versions of the standard, instead of the above two
-            # properties , just the following characters were used:
-            $perl_case_ignorable +=
-                            ord("'")
-                        +   utf8::unicode_to_native(0xAD)  # SOFT HYPHEN (SHY)
-                        +   0x2019; # RIGHT SINGLE QUOTATION MARK
-        }
-    }
-
     # The remaining perl defined tables are mostly based on Unicode TR 18,
     # "Annex C: Compatibility Properties".  All of these have two versions,
     # one whose name generally begins with Posix that is posix-compliant, and