[interpreter] Fix debug stepping for generators.

src/interpreter/bytecode-generator.cc

 // Copyright 2015 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/interpreter/bytecode-generator.h"
 
 #include "src/ast/scopes.h"
 #include "src/code-stubs.h"
 #include "src/compiler.h"
 #include "src/interpreter/bytecode-register-allocator.h"
@@ skipping 196 matching lines @@
   explicit ControlScopeForTopLevel(BytecodeGenerator* generator)
       : ControlScope(generator) {}
 
  protected:
   bool Execute(Command command, Statement* statement) override {
     switch (command) {
       case CMD_BREAK:  // We should never see break/continue in top-level.
       case CMD_CONTINUE:
         UNREACHABLE();
       case CMD_RETURN:
-        generator()->builder()->SetReturnPosition();
         generator()->builder()->Return();
         return true;
       case CMD_RETHROW:
         generator()->builder()->ReThrow();
         return true;
     }
     return false;
   }
 };
 
@@ skipping 2054 matching lines @@
       Register done = register_allocator()->NextConsecutiveRegister();
       builder()
           ->MoveRegister(input, value)
           .LoadTrue()
           .StoreAccumulatorInRegister(done)
           .CallRuntime(Runtime::kInlineCreateIterResultObject, value, 2);
       execution_control()->ReturnAccumulator();
     }
 
     builder()->Bind(&resume_with_throw);
+    builder()->SetExpressionPosition(expr);
     builder()->LoadAccumulatorWithRegister(input).Throw();
 
     builder()->Bind(&resume_with_next);
     builder()->LoadAccumulatorWithRegister(input);
   }
   execution_result()->SetResultInAccumulator();
 }
 
 void BytecodeGenerator::VisitThrow(Throw* expr) {
   VisitForAccumulatorValue(expr->exception());
@@ skipping 894 matching lines @@
   return execution_context()->scope()->language_mode();
 }
 
 int BytecodeGenerator::feedback_index(FeedbackVectorSlot slot) const {
   return TypeFeedbackVector::GetIndex(slot);
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8