patch for returning Nil for failed matches

nil.diff

diff --git a/src/core/Cursor.pm b/src/core/Cursor.pm
index 2654bfe..d6f81c8 100644
--- a/src/core/Cursor.pm
+++ b/src/core/Cursor.pm
@@ -41,8 +41,11 @@ my class Cursor does NQPCursorRole {
 
     method MATCH_SAVE() {
         my $match := self.MATCH();
-        $last_match := $match if $match;
-        $match;
+        if $match {
+            $last_match := $match;
+            return $match
+        }
+        Nil
     }
 
     # INTERPOLATE will iterate over the string $tgt beginning at position 0.
@@ -79,7 +82,7 @@ my class Cursor does NQPCursorRole {
                     $match := nqp::substr($tgt, $pos, $eos - $pos) ~~ $topic;
                     # In order to return the correct result we need to match from the
                     # current position only.
-                    next if $match.from;
+                    next if !$match || $match.from;
                     $match := ~$match;
                     $len   := nqp::chars( $match );
                 }