[Interpreter] Enable assignments in expressions.

test/unittests/interpreter/bytecode-array-builder-unittest.cc

 // Copyright 2014 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/v8.h"
 
 #include "src/interpreter/bytecode-array-builder.h"
 #include "src/interpreter/bytecode-array-iterator.h"
 #include "test/unittests/test-utils.h"
 
 namespace v8 {
 namespace internal {
 namespace interpreter {
 
 class BytecodeArrayBuilderTest : public TestWithIsolateAndZone {
  public:
   BytecodeArrayBuilderTest() {}
   ~BytecodeArrayBuilderTest() override {}
 };
 
 
 TEST_F(BytecodeArrayBuilderTest, AllBytecodesGenerated) {
   BytecodeArrayBuilder builder(isolate(), zone());
 
-  builder.set_locals_count(1);
+  builder.set_locals_count(2);
   builder.set_context_count(1);
   builder.set_parameter_count(0);
-  CHECK_EQ(builder.locals_count(), 1);
+  CHECK_EQ(builder.locals_count(), 2);
   CHECK_EQ(builder.context_count(), 1);
-  CHECK_EQ(builder.fixed_register_count(), 2);
+  CHECK_EQ(builder.fixed_register_count(), 3);
 
   // Emit constant loads.
   builder.LoadLiteral(Smi::FromInt(0))
       .LoadLiteral(Smi::FromInt(8))
       .LoadLiteral(Smi::FromInt(10000000))
       .LoadUndefined()
       .LoadNull()
       .LoadTheHole()
       .LoadTrue()
       .LoadFalse();
 
   // Emit accumulator transfers.
   Register reg(0);
   builder.LoadAccumulatorWithRegister(reg).StoreAccumulatorInRegister(reg);
 
+  // Emit register-register transfer.
+  Register other(1);
+  builder.MoveRegister(reg, other);
+
   // Emit global load / store operations.
   builder.LoadGlobal(0, 1, LanguageMode::SLOPPY, TypeofMode::NOT_INSIDE_TYPEOF)
       .LoadGlobal(0, 1, LanguageMode::STRICT, TypeofMode::NOT_INSIDE_TYPEOF)
       .LoadGlobal(0, 1, LanguageMode::SLOPPY, TypeofMode::INSIDE_TYPEOF)
       .LoadGlobal(0, 1, LanguageMode::STRICT, TypeofMode::INSIDE_TYPEOF)
       .StoreGlobal(0, 1, LanguageMode::SLOPPY)
       .StoreGlobal(0, 1, LanguageMode::STRICT);
 
   // Emit wide global load / store operations.
   builder.LoadGlobal(0, 1024, LanguageMode::SLOPPY,
@@ skipping 642 matching lines @@
 
   CHECK_EQ(iterator.current_bytecode(), Bytecode::kReturn);
   iterator.Advance();
   CHECK(iterator.done());
 }
 
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8