Parse arrow functions at proper precedence level

src/pattern-rewriter.cc

Index: src/pattern-rewriter.cc
diff --git a/src/pattern-rewriter.cc b/src/pattern-rewriter.cc
index f3ecf7f1542dd658f3f2bbfc789f7d19381b4efc..489530d47750bafe3a520d6faf37ab494163e2ea 100644
--- a/src/pattern-rewriter.cc
+++ b/src/pattern-rewriter.cc
@@ -364,7 +364,12 @@ void Parser::PatternRewriter::VisitAssignment(Assignment* node) {
 
 
 void Parser::PatternRewriter::VisitSpread(Spread* node) {
-  // TODO(dslomov): implement.
+  UNREACHABLE();
+}
+
+
+void Parser::PatternRewriter::VisitEmptyParentheses(EmptyParentheses* node) {
+  UNREACHABLE();
 }