Forward accept_IN to ParseYieldExpression

This allows "yield 'x' in o" as an expression in a generator.

R=ishell@chromium.org
BUG=v8:4945
LOG=n

Review URL: https://codereview.chromium.org/1916183003

Cr-Commit-Position: refs/heads/master@{#35798}

src/parsing/parser-base.h

@@ -773,7 +773,8 @@ class ParserBase : public Traits {
   ExpressionT ParseAssignmentExpression(bool accept_IN,
                                         ExpressionClassifier* classifier,
                                         bool* ok);
-  ExpressionT ParseYieldExpression(ExpressionClassifier* classifier, bool* ok);
+  ExpressionT ParseYieldExpression(bool accept_IN,
+                                   ExpressionClassifier* classifier, bool* ok);
   ExpressionT ParseConditionalExpression(bool accept_IN,
                                          ExpressionClassifier* classifier,
                                          bool* ok);
@@ -1896,7 +1897,7 @@ ParserBase<Traits>::ParseAssignmentExpression(bool accept_IN,
   int lhs_beg_pos = peek_position();
 
   if (peek() == Token::YIELD && is_generator()) {
-    return this->ParseYieldExpression(classifier, ok);
+    return this->ParseYieldExpression(accept_IN, classifier, ok);
   }
 
   FuncNameInferrer::State fni_state(fni_);
@@ -2043,7 +2044,8 @@ ParserBase<Traits>::ParseAssignmentExpression(bool accept_IN,
 
 template <class Traits>
 typename ParserBase<Traits>::ExpressionT
-ParserBase<Traits>::ParseYieldExpression(ExpressionClassifier* classifier,
+ParserBase<Traits>::ParseYieldExpression(bool accept_IN,
+                                         ExpressionClassifier* classifier,
                                          bool* ok) {
   // YieldExpression ::
   //   'yield' ([no line terminator] '*'? AssignmentExpression)?
@@ -2073,7 +2075,7 @@ ParserBase<Traits>::ParseYieldExpression(ExpressionClassifier* classifier,
         if (!delegating) break;
         // Delegating yields require an RHS; fall through.
       default:
-        expression = ParseAssignmentExpression(false, classifier, CHECK_OK);
+        expression = ParseAssignmentExpression(accept_IN, classifier, CHECK_OK);
         Traits::RewriteNonPattern(classifier, CHECK_OK);
         break;
     }

test/cctest/test-parsing.cc

@@ -2395,6 +2395,10 @@ TEST(ErrorsYieldGenerator) {
     "var {foo: yield 24} = {a: 42};",
     "[yield 24] = [42];",
     "({a: yield 24} = {a: 42});",
+    "for (yield 'x' in {});",
+    "for (yield 'x' of {});",
+    "for (yield 'x' in {} in {});",
+    "for (yield 'x' in {} of {});",
     NULL
   };
   // clang-format on

test/mjsunit/regress/regress-4945.js

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+function* g(o) {
+  yield 'x' in o;
+}
+
+assertTrue(g({x: 1}).next().value);
+assertFalse(g({}).next().value);