[test] add testcase for double-quoted lex names GH #1095

in perl6 the correctly double-quoted .lex "foo\\o", $P3 name fails to work.
see https://rt.perl.org/Public/Bug/Display.html?id=116643
this might be caused by the switch from globals to lexicals, as this statement
is now enclosed in a block.

in parrot the binary character \0 causes problems in lexnames with roundtrips.

t/compilers/imcc/syn/clash.t

@@ -1,13 +1,13 @@
 #!perl
-# Copyright (C) 2001-2014, Parrot Foundation.
+# Copyright (C) 2001-2009,2014, Parrot Foundation.
 
 use strict;
 use warnings;
 use lib qw( . lib ../lib ../../lib );
 
 use Test::More;
 use Parrot::Config;
-use Parrot::Test tests => 13;
+use Parrot::Test tests => 14;
 
 pir_output_is( <<'CODE', <<'OUT', "if/unless" );
 .sub test :main
@@ -232,6 +232,33 @@ CODE
 /Multiple declarations of lexical 'foo'/
 OUT
 
+# perl6 has a similar issue but there testcase 2 failed. RT #116643
+pir_output_is( <<'CODE', <<'OUT', 'double-quoted .lex names', todo => 'GH #1095');
+.sub 'main' :main
+    .lex 'bar\o', $P0
+    $P1 = box 'ok 1'
+    store_lex 'bar\o', $P1
+    $P2 = find_lex 'bar\o'
+    say $P2
+
+    .lex "foo\\o", $P3
+    $P1 = box 'ok 2'
+    store_lex "foo\\o", $P1
+    $P2 = find_lex "foo\\o"
+    say $P2
+
+    .lex "foo\o", $P4
+    $P1 = box 'ok 3'
+    store_lex "foo\o", $P1
+    $P2 = find_lex "foo\o"
+    say $P2
+.end
+CODE
+ok 1
+ok 2
+ok 3
+OUT
+
 # Local Variables:
 #   mode: cperl
 #   cperl-indent-level: 4