[parser] Fix tail calls in for in/of loops

src/parsing/parser.cc

 // Copyright 2012 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.
 
 #include "src/parsing/parser.h"
 
 #include <memory>
 
 #include "src/api.h"
 #include "src/ast/ast-expression-rewriter.h"
@@ skipping 2643 matching lines @@
         if (mode == ForEachStatement::ITERATE) {
           ExpressionClassifier classifier(this);
           enumerable = ParseAssignmentExpression(true, CHECK_OK);
           RewriteNonPattern(CHECK_OK);
         } else {
           enumerable = ParseExpression(true, CHECK_OK);
         }
 
         Expect(Token::RPAREN, CHECK_OK);
 
-        // For legacy compat reasons, give for loops similar treatment to
-        // if statements in allowing a function declaration for a body
-        Statement* body = ParseScopedStatement(NULL, true, CHECK_OK);
-        Statement* final_loop = InitializeForEachStatement(
-            loop, expression, enumerable, body, each_keyword_position);
+        {
+          ReturnExprScope no_tail_calls(function_state_,
+                                        ReturnExprContext::kInsideForInOfBody);
+          BlockState block_state(&scope_state_);
+          block_state.set_start_position(scanner()->location().beg_pos);
 
-        DCHECK_NULL(for_state.FinalizedBlockScope());
-        return final_loop;
+          // For legacy compat reasons, give for loops similar treatment to
+          // if statements in allowing a function declaration for a body
+          Statement* body = ParseScopedStatement(NULL, true, CHECK_OK);
+          block_state.set_end_position(scanner()->location().end_pos);
+          Statement* final_loop = InitializeForEachStatement(
+              loop, expression, enumerable, body, each_keyword_position);
 
+          DCHECK_NULL(for_state.FinalizedBlockScope());
+          return final_loop;
+        }
       } else {
         init = factory()->NewExpressionStatement(expression, lhs_beg_pos);
       }
     }
   }
 
   // Standard 'for' loop
   ForStatement* loop = factory()->NewForStatement(labels, stmt_pos);
   ParserTarget target(this, loop);
 
@@ skipping 2944 matching lines @@
   node->Print(Isolate::Current());
 }
 #endif  // DEBUG
 
 #undef CHECK_OK
 #undef CHECK_OK_VOID
 #undef CHECK_FAILED
 
 }  // namespace internal
 }  // namespace v8