[Interpreter] Add ValidBytecodeOperandSizeCombinationsIterator.

src/interpreter/bytecodes.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/interpreter/bytecodes.h"
 
 #include <iomanip>
 
 #include "src/frames.h"
 #include "src/interpreter/bytecode-traits.h"
@@ skipping 679 matching lines @@
       s << "a" << parameter_index - 1;
       return s.str();
     }
   } else {
     std::ostringstream s;
     s << "r" << index();
     return s.str();
   }
 }
 
+ValidBytecodeOperandSizeCombinationsIterator::
+    ValidBytecodeOperandSizeCombinationsIterator()
+    : reached_end_(false),
+      operand_scale_(OperandScale::kSingle),
+      bytecode_(kFirstBytecode) {
+  // Advance to the first valid combination
+  while (!done() && !CurrentCombinationIsValid()) {
+    IncrementPosition();
+  }
+  DCHECK(!done());
+}
+
+void ValidBytecodeOperandSizeCombinationsIterator::Advance() {
+  do {
+    IncrementPosition();
+  } while (!done() && !CurrentCombinationIsValid());
+}
+
+void ValidBytecodeOperandSizeCombinationsIterator::IncrementPosition() {
+  if (bytecode_ == Bytecode::kLast) {
+    if (operand_scale_ == OperandScale::kMaxValid) {
+      reached_end_ = true;
+      return;
+    }
+    bytecode_ = kFirstBytecode;
+    operand_scale_ = Bytecodes::NextOperandScale(operand_scale_);
+  } else {
+    bytecode_ = Bytecodes::FromByte(static_cast<int>(bytecode_) + 1);
+  }
+}
+
+bool ValidBytecodeOperandSizeCombinationsIterator::CurrentCombinationIsValid() {
+  return Bytecodes::BytecodeHasHandler(bytecode_, operand_scale_);
+}
+
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8