[Interpreter] Optimize the Register Optimizer.

src/interpreter/bytecode-peephole-optimizer.cc

Index: src/interpreter/bytecode-peephole-optimizer.cc
diff --git a/src/interpreter/bytecode-peephole-optimizer.cc b/src/interpreter/bytecode-peephole-optimizer.cc
index c87d31c39f04aef43254e8643af83c2672b1d8c6..c36dfd06de83e58968847bfc8017c2f262b2b9c6 100644
--- a/src/interpreter/bytecode-peephole-optimizer.cc
+++ b/src/interpreter/bytecode-peephole-optimizer.cc
@@ -13,7 +13,7 @@ namespace interpreter {
 
 BytecodePeepholeOptimizer::BytecodePeepholeOptimizer(
     BytecodePipelineStage* next_stage)
-    : next_stage_(next_stage), last_(Bytecode::kIllegal) {
+    : next_stage_(next_stage), last_(Bytecode::kIllegal, BytecodeSourceInfo()) {
   InvalidateLast();
 }
 
@@ -77,8 +77,7 @@ void BytecodePeepholeOptimizer::SetLast(const BytecodeNode* const node) {
   // source position information. NOP without source information can
   // always be elided.
   DCHECK(node->bytecode() != Bytecode::kNop || node->source_info().is_valid());
-
-  last_.Clone(node);
+  last_ = *node;
 }
 
 bool BytecodePeepholeOptimizer::CanElideLastBasedOnSourcePosition(