Test where with regex + block

Closes rakudo/rakudo#1481
Rakudo fix: rakudo/rakudo@c0c7756f4b

Author: zoffixznet

S05-metasyntax/regex.t

@@ -3,7 +3,7 @@ use lib <t/spec/packages/>;
 use Test;
 use Test::Util;
 
-plan 51;
+plan 52;
 
 throws-like 'qr/foo/', X::Obsolete, 'qr// is gone';
 
@@ -280,4 +280,15 @@ is ~("ddd" ~~ / [ x | d ] **? 2..3 /), "dd", 'frugal match with alternation';
 is_run ｢/a/; print "pass"｣, {:out<pass>, :err(''), :0status},
     '/a/ in sink context in in uppermost scope does not explode';
 
+# https://github.com/rakudo/rakudo/issues/1481
+{
+    my @res;
+    multi sub foo($x where /{@res.push: $x}./) {}
+    multi sub foo($y where /{@res.push: $y}./) {}
+    foo 'a';
+    foo 'b';
+    is-deeply @res, [<a a b b>],
+        'regex blocks update their lexical variables right';
+}
+
 # vim: ft=perl6