Make \($x,$y) assignment work

This applies to \ with multiple kids (refgen).  Up till now,
op_lvalue_flags only handled srefgen (single refgen).

Before I was converting srefgen to lvref and nulling the kid op:

  srefgen
    ex-list
      rv2sv
        gv

became:

  lvref
    ex-list
      ex-rv2sv
        gv

Now I’m converting the kid instead and nulling the srefgen:

  ex-srefgen
    ex-list
      lvref
        gv

so that the same code can apply to refgen:

  refgen
    ex-list
      pushmark
      rv2sv
        gv
      rv2sv
        gv

becomes

  ex-refgen
    ex-list
      ex-pushmark
      lvref
        gv
      lvref
        gv

1 files changed, 3 insertions, 1 deletions

diff --git a/t/op/ref.t b/t/op/ref.t
index 8c9e3fd302..dbd532271c 100644
--- a/t/op/ref.t
+++ b/t/op/ref.t
@@ -319,8 +319,10 @@ is (scalar grep(ref($_), @baa), 3);
 is (scalar (@bzz), 3);
 
 # also, it can't be an lvalue
+# (That’s what *you* think!  --sprout)
 eval '\\($x, $y) = (1, 2);';
-like ($@, qr/Can\'t modify.*ref.*in.*assignment/);
+like ($@, qr/Can\'t modify.*ref.*in.*assignment(?x:
+           )|Experimental lvalue references not enabled/);
 
 # test for proper destruction of lexical objects
 $test = curr_test();