[interpreter] Add support for scalable operands.

src/interpreter/interpreter.h

Index: src/interpreter/interpreter.h
diff --git a/src/interpreter/interpreter.h b/src/interpreter/interpreter.h
index 42b9bd7f9e8f9b8d5168003633347a0cf7d5af7e..b77a4ff8c5847474674535fa5ef60697f9ce8c2e 100644
--- a/src/interpreter/interpreter.h
+++ b/src/interpreter/interpreter.h
@@ -40,7 +40,7 @@ class Interpreter {
   static bool MakeBytecode(CompilationInfo* info);
 
   // Return bytecode handler for |bytecode|.
-  Code* GetBytecodeHandler(Bytecode bytecode);
+  Code* GetBytecodeHandler(Bytecode bytecode, int operand_scale);
 
   // GC support.
   void IterateDispatchTable(ObjectVisitor* v);
@@ -128,9 +128,13 @@ class Interpreter {
   void DoStoreLookupSlot(LanguageMode language_mode,
                          InterpreterAssembler* assembler);
 
+  // Get dispatch table index of bytecode.
+  size_t GetDispatchTableIndex(Bytecode bytecode, uint32_t operand_size_log2);
+
   bool IsDispatchTableInitialized();
 
-  static const int kDispatchTableSize = static_cast<int>(Bytecode::kLast) + 1;
+  static const int kNumberOfWideVariants = 3;
+  static const int kDispatchTableSize = kNumberOfWideVariants * (kMaxUInt8 + 1);
 
   Isolate* isolate_;
   Code* dispatch_table_[kDispatchTableSize];