[Interpreter] Preserve source positions in peephole optimizer.

src/interpreter/bytecodes.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/bytecodes.h"
 
 #include <iomanip>
 
 #include "src/frames.h"
 #include "src/interpreter/bytecode-traits.h"
@@ skipping 471 matching lines @@
     case Bytecode::kDebugBreakExtraWide:
     case Bytecode::kWide:
     case Bytecode::kDebugBreakWide:
       return true;
     default:
       return false;
   }
 }
 
 // static
+bool Bytecodes::IsWithoutExternalSideEffects(Bytecode bytecode) {
+  // These bytecodes only manipulate interpreter frame state and will
+  // never throw.
+  return (IsAccumulatorLoadWithoutEffects(bytecode) || IsLdarOrStar(bytecode) ||
+          bytecode == Bytecode::kMov || bytecode == Bytecode::kNop ||
+          IsJump(bytecode));
+}
+
+// static
 bool Bytecodes::IsJumpOrReturn(Bytecode bytecode) {
   return bytecode == Bytecode::kReturn || IsJump(bytecode);
 }
 
 // static
 bool Bytecodes::IsMaybeRegisterOperandType(OperandType operand_type) {
   return operand_type == OperandType::kMaybeReg;
 }
 
 // static
@@ skipping 426 matching lines @@
   } else {
     std::ostringstream s;
     s << "r" << index();
     return s.str();
   }
 }
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8