[debugger] fix break locations for assignments and return.

src/interpreter/bytecode-array-builder.h

Index: src/interpreter/bytecode-array-builder.h
diff --git a/src/interpreter/bytecode-array-builder.h b/src/interpreter/bytecode-array-builder.h
index fe693371845c3f56c12d10e37a37debe1552aad3..d10761dd10f2b3318baf980f928a0d45e8f6bd7b 100644
--- a/src/interpreter/bytecode-array-builder.h
+++ b/src/interpreter/bytecode-array-builder.h
@@ -257,6 +257,8 @@ class BytecodeArrayBuilder final : public ZoneObject, private RegisterMover {
   // entry, so that it can be referenced by above exception handling support.
   int NewHandlerEntry() { return handler_table_builder()->NewHandlerEntry(); }
 
+  void InitializeReturnPosition(FunctionLiteral* literal);
+
   void SetStatementPosition(Statement* stmt);
   void SetExpressionPosition(Expression* expr);
 
@@ -334,8 +336,8 @@ class BytecodeArrayBuilder final : public ZoneObject, private RegisterMover {
   bool NeedToBooleanCast();
   bool IsRegisterInAccumulator(Register reg);
 
-  // Set position for implicit return.
-  void SetReturnPosition(FunctionLiteral* fun);
+  // Set position for return.
+  void SetReturnPosition();
 
   // Gets a constant pool entry for the |object|.
   size_t GetConstantPoolEntry(Handle<Object> object);
@@ -371,6 +373,7 @@ class BytecodeArrayBuilder final : public ZoneObject, private RegisterMover {
   int parameter_count_;
   int local_register_count_;
   int context_register_count_;
+  int return_position_;
   TemporaryRegisterAllocator temporary_allocator_;
   RegisterTranslator register_translator_;