proper return value for smartmatching against a substitution

We will return True if there was a match, otherwise False.
If the rhs is not a substitution, we still will call ACCEPTS
and return its result.

src/Perl6/Actions.pm

@@ -4164,14 +4164,32 @@ class Perl6::Actions is HLL::Actions does STDActions {
         my $rhs := $/[1].ast;
         my $old_topic_var := $lhs.unique('old_topic');
         my $result_var := $lhs.unique('sm_result');
-        my $sm_call := QAST::Op.new(
-            :op('callmethod'), :name('ACCEPTS'),
-            $rhs,
-            QAST::Var.new( :name('$_'), :scope('lexical') )
-        );
+        my $sm_call;
+
+        # In case the rhs is a substitution, the result should say if it actually
+        # matched something. Calling ACCEPTS will always be True for this case.
+        if $rhs<is_subst> {
+            $sm_call := QAST::Stmt.new(
+                $rhs,
+                QAST::Op.new(
+                    :op('callmethod'), :name('Bool'),
+                    QAST::Var.new( :name('$/'), :scope('lexical') )
+                )
+            );
+        }
+        else {
+            # Call $rhs.ACCEPTS( $_ ), where $_ is $lhs.
+            $sm_call := QAST::Op.new(
+                :op('callmethod'), :name('ACCEPTS'),
+                $rhs,
+                QAST::Var.new( :name('$_'), :scope('lexical') )
+            );
+        }
+
         if $negated {
             $sm_call := QAST::Op.new( :op('call'), :name('&prefix:<!>'), $sm_call );
         }
+
         QAST::Stmt.new(
             # Stash original $_.
             QAST::Op.new( :op('bind'),
@@ -5001,16 +5019,17 @@ class Perl6::Actions is HLL::Actions does STDActions {
         }
         $past.push(QAST::IVal.new(:named('SET_CALLER_DOLLAR_SLASH'), :value(1)));
 
-        $past := QAST::Op.new(
+        $past := make QAST::Op.new(
             :node($/),
             :op('call'),
             :name('&infix:<=>'),
             QAST::Var.new(:name('$_'), :scope('lexical')),
             $past
         );
 
-        make $past;
-    }
+        $past<is_subst> := 1;
+        $past
+}
 
     method quote:sym<quasi>($/) {
         my $ast_class := $*W.find_symbol(['AST']);