Fix bug with nested spreads as patterns

src/parsing/pattern-rewriter.cc

Index: src/parsing/pattern-rewriter.cc
diff --git a/src/parsing/pattern-rewriter.cc b/src/parsing/pattern-rewriter.cc
index af6060a44ba992f20191478a472190b9399bb333..e5211b41947156c64bf9477ec83015a69ec059ad 100644
--- a/src/parsing/pattern-rewriter.cc
+++ b/src/parsing/pattern-rewriter.cc
@@ -261,12 +261,14 @@ Variable* Parser::PatternRewriter::CreateTempVar(Expression* value) {
 void Parser::PatternRewriter::VisitRewritableExpression(
     RewritableExpression* node) {
   // If this is not a destructuring assignment...
-  if (!IsAssignmentContext() || !node->expression()->IsAssignment()) {
+  if (!IsAssignmentContext()) {
     // Mark the node as rewritten to prevent redundant rewriting, and
     // perform BindingPattern rewriting
     DCHECK(!node->is_rewritten());
     node->Rewrite(node->expression());
     return Visit(node->expression());
+  } else if (!node->expression()->IsAssignment()) {
+    return Visit(node->expression());

[caitp, 2016/09/01 15:34:41]

my understanding is, this will recursively continue the rewriting from the
Visit(node->expression()) 2 lines above this, right?

I think it looks okay, but I'm not sure why the nested pattern would be a
RewritableExpression in the first place

   }
 
   if (node->is_rewritten()) return;