mktables: Handle Unicode 16.0 Unikemet.txt file

This is handled by ignoring it for now, and letting mktables know that
the properties it contains are empty.  This file, new in 16.0, gives
extra information about Egyption Hieroglyphics newly encoded in 16.0.
It is intended only for scholars of these ancient symbols.

mktables normally handles new properties automatically, but this file is
in a completely different format than previous ones, so mktables would
have to be adapted to understand that.  That might not be too hard,
given that mktables has infrastructue to handle other outliers that have
come along over the years from Unicode.  But, by ignoring this file, we
create empty tables which generate errors in other places in perl.
These are real bugs that ought to be fixed, and will be before 16.0 is
incoroporated into blead.  And how many Egyptologists are there in the
world, much less how many use the latest Perl?

So the perldelta will say that 16.0's support doesn't include these,
which are mostly provisional anyway.

Author: khwilliamson

lib/unicore/mktables

@@ -871,6 +871,15 @@ push @tables_that_may_be_empty, 'Grapheme_Cluster_Break=Prepend'
 push @tables_that_may_be_empty, 'Canonical_Combining_Class=CCC133'
                                                     if $v_version ge v6.2.0;
 
+# These properties of Egyptian hieroglyphs are not handled by Perl.  Their
+# intended audience is only specialist Egyptologists
+push @tables_that_may_be_empty, qw(kEH_Cat kEH_Desc kEH_HG kEH_IFAO
+                                   kEH_JSesh
+                                   kEH_NoMirror kEH_NoMirror=Yes
+                                   kEH_NoMirror=No
+                                   kEH_NoRotate kEH_NoRotate=Yes)
+                                                    if $v_version ge v16.0.0;
+
 # The lists below are hashes, so the key is the item in the list, and the
 # value is the reason why it is in the list.  This makes generation of
 # documentation easier.
@@ -19869,6 +19878,12 @@ my @input_file_objects = (
                     Skip => $Unused_Skip,
                     UCD => 0,
                    ),
+    Input_file->new('Unikemet.txt', v16.0.0,
+                    # For Egyptian Hieroglyphs; is in an alien format to the
+                    # other files Unicode furnishes.
+                    Skip => $Unused_Skip,
+                    UCD => 0,
+                   ),
 );
 
 # End of all the preliminaries.