perlop/smartmatch: now a "feature" and discouraged, not experimental

Author: tonycoz

pod/perlop.pod

@@ -682,13 +682,21 @@ C<use v5.36> (or higher) declaration in the current scope.
 
 =head2 Smartmatch Operator
 
-First available in Perl 5.10.1 (the 5.10.0 version behaved differently),
-binary C<~~> does a "smartmatch" between its arguments.  This is mostly
+The C<smartmatch> feature is discouraged for new code and retained for
+backward compatibility.
+
+The smartmatch operator was introduced in 5.10.0 had significant
+changes in 5.10.1.  It is enabled by default and in all feature
+bundles up to 5.40.  To use smartmatch with a later feature bundle you
+will need enable it explicitly:
+
+  use v5.42;
+  use feature "smartmatch";
+
+Binary C<~~> does a "smartmatch" between its arguments.  This is mostly
 used implicitly in the C<when> construct described in L<perlsyn>, although
 not all C<when> clauses call the smartmatch operator.  Unique among all of
-Perl's operators, the smartmatch operator can recurse.  The smartmatch
-operator is L<experimental|perlpolicy/experimental> and its behavior is
-subject to change.
+Perl's operators, the smartmatch operator can recurse.
 
 It is also unique in that all other Perl operators impose a context
 (usually string or numeric context) on their operands, autoconverting