[interpreter] Bytecode register optimizer.

src/interpreter/bytecode-pipeline.cc

Index: src/interpreter/bytecode-pipeline.cc
diff --git a/src/interpreter/bytecode-pipeline.cc b/src/interpreter/bytecode-pipeline.cc
index 07ce6ed5d2eb09f57a2a85c95ff2fcd7f3aa1010..5812c89954d51a8c369388ecec194662001eeccc 100644
--- a/src/interpreter/bytecode-pipeline.cc
+++ b/src/interpreter/bytecode-pipeline.cc
@@ -12,6 +12,8 @@ namespace internal {
 namespace interpreter {
 
 void BytecodeSourceInfo::Update(const BytecodeSourceInfo& entry) {
+  if (!entry.is_valid()) return;
+
   if (!is_valid() || (entry.is_statement() && !is_statement()) ||
       (entry.is_statement() && is_statement() &&
        entry.source_position() > source_position())) {
@@ -75,6 +77,15 @@ BytecodeNode::BytecodeNode(Bytecode bytecode, uint32_t operand0,
   operand_scale_ = operand_scale;
 }
 
+BytecodeNode::BytecodeNode(const BytecodeNode& other) {
+  memcpy(this, &other, sizeof(other));
+}
+
+BytecodeNode& BytecodeNode::operator=(const BytecodeNode& other) {
+  memcpy(this, &other, sizeof(other));
+  return *this;
+}
+
 void BytecodeNode::set_bytecode(Bytecode bytecode) {
   DCHECK_EQ(Bytecodes::NumberOfOperands(bytecode), 0);
   bytecode_ = bytecode;