[interpreter] Implement support for the --trace flag.

src/interpreter/bytecode-array-builder.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-array-builder.h"
 
 #include "src/globals.h"
 #include "src/interpreter/bytecode-array-writer.h"
 #include "src/interpreter/bytecode-dead-code-optimizer.h"
 #include "src/interpreter/bytecode-label.h"
@@ skipping 698 matching lines @@
   return *this;
 }
 
 BytecodeArrayBuilder& BytecodeArrayBuilder::MarkTryEnd(int handler_id) {
   BytecodeLabel try_end;
   Bind(&try_end);
   handler_table_builder()->SetTryRegionEnd(handler_id, try_end.offset());
   return *this;
 }
 
-void BytecodeArrayBuilder::EnsureReturn() {
-  if (!return_seen_in_block_) {
-    LoadUndefined();
-    Return();
-  }
-  DCHECK(return_seen_in_block_);
-}
-
 BytecodeArrayBuilder& BytecodeArrayBuilder::Call(Register callable,
                                                  RegisterList args,
                                                  int feedback_slot,
                                                  TailCallMode tail_call_mode) {
   if (tail_call_mode == TailCallMode::kDisallow) {
     Output(Bytecode::kCall, RegisterOperand(callable),
            RegisterOperand(args.first_register()),
            UnsignedOperand(args.register_count()),
            UnsignedOperand(feedback_slot));
   } else {
@@ skipping 195 matching lines @@
       }
     }
   }
 
   return true;
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8