[interpreter] Introduce fused bytecodes for common sequences.

src/interpreter/bytecode-pipeline.h

Index: src/interpreter/bytecode-pipeline.h
diff --git a/src/interpreter/bytecode-pipeline.h b/src/interpreter/bytecode-pipeline.h
index ade712c92c323db41759cd17766ca7e5bfb5f361..81590683d12eaad551f18d4b5ba9dc55c5f56bb3 100644
--- a/src/interpreter/bytecode-pipeline.h
+++ b/src/interpreter/bytecode-pipeline.h
@@ -100,6 +100,11 @@ class BytecodeNode final : ZoneObject {
   // Return the size when this node is serialized to a bytecode array.
   size_t Size() const;
 
+  // Transform to a node representing |new_bytecode| which has one
+  // operand more than the current bytecode.
+  void Transform(Bytecode new_bytecode, uint32_t extra_operand,
+                 OperandScale extra_operand_scale);
+
   Bytecode bytecode() const { return bytecode_; }
 
   uint32_t operand(int i) const {