[interpreter] Ensure optimizations preserve source positions.

src/interpreter/bytecodes.cc

Index: src/interpreter/bytecodes.cc
diff --git a/src/interpreter/bytecodes.cc b/src/interpreter/bytecodes.cc
index 46134b7f1d418c52dbecbfe82775ad20586f08cf..e626acc69022e88089d4b9f3d20ff86689c73d52 100644
--- a/src/interpreter/bytecodes.cc
+++ b/src/interpreter/bytecodes.cc
@@ -107,7 +107,6 @@ Bytecode Bytecodes::FromByte(uint8_t value) {
   return bytecode;
 }
 
-
 // static
 Bytecode Bytecodes::GetDebugBreak(Bytecode bytecode) {
   DCHECK(!IsDebugBreak(bytecode));
@@ -140,7 +139,6 @@ int Bytecodes::Size(Bytecode bytecode, OperandScale operand_scale) {
   return size;
 }
 
-
 // static
 size_t Bytecodes::ReturnCount(Bytecode bytecode) {
   return bytecode == Bytecode::kReturn ? 1 : 0;
@@ -160,7 +158,6 @@ int Bytecodes::NumberOfOperands(Bytecode bytecode) {
   return 0;
 }
 
-
 // static
 int Bytecodes::NumberOfRegisterOperands(Bytecode bytecode) {
   DCHECK(bytecode <= Bytecode::kLast);
@@ -277,6 +274,34 @@ bool Bytecodes::IsAccumulatorLoadWithoutEffects(Bytecode bytecode) {
 }
 
 // static
+bool Bytecodes::IsJumpWithoutEffects(Bytecode bytecode) {
+  return IsJump(bytecode) && !IsJumpIfToBoolean(bytecode);
+}
+
+// static
+bool Bytecodes::IsRegisterLoadWithoutEffects(Bytecode bytecode) {
+  switch (bytecode) {
+    case Bytecode::kMov:
+    case Bytecode::kPopContext:
+    case Bytecode::kPushContext:
+    case Bytecode::kStar:
+    case Bytecode::kLdrUndefined:
+      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) ||
+          IsRegisterLoadWithoutEffects(bytecode) ||
+          bytecode == Bytecode::kNop || IsJumpWithoutEffects(bytecode));
+}
+
+// static
 OperandType Bytecodes::GetOperandType(Bytecode bytecode, int i) {
   DCHECK_LE(bytecode, Bytecode::kLast);
   DCHECK_LT(i, NumberOfOperands(bytecode));
@@ -488,15 +513,6 @@ bool Bytecodes::IsPrefixScalingBytecode(Bytecode bytecode) {
 }
 
 // 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);
 }