[test] make instruction sequence test emit cfgs more like the scheduler

test/unittests/compiler/move-optimizer-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/compiler/move-optimizer.h"
 #include "test/unittests/compiler/instruction-sequence-unittest.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
@@ skipping 118 matching lines @@
   EndBlock(Jump(2));
   AddMove(LastInstruction(), Reg(0), Reg(1));
 
   StartBlock();
   EndBlock(Jump(1));
   AddMove(LastInstruction(), Reg(0), Reg(1));
 
   StartBlock();
   EndBlock(Last());
 
+  auto last = LastInstruction();
+
   Optimize();
 
-  auto move = LastInstruction()->parallel_moves()[0];
+  auto move = last->parallel_moves()[0];
   CHECK_EQ(1, NonRedundantSize(move));
   CHECK(Contains(move, Reg(0), Reg(1)));
 }
 
 
 TEST_F(MoveOptimizerTest, SimpleMergeCycle) {
   StartBlock();
   EndBlock(Branch(Imm(), 1, 2));
 
   StartBlock();
   EndBlock(Jump(2));
   auto gap_0 = LastInstruction();
   AddMove(gap_0, Reg(0), Reg(1));
   AddMove(LastInstruction(), Reg(1), Reg(0));
 
   StartBlock();
   EndBlock(Jump(1));
   auto gap_1 = LastInstruction();
   AddMove(gap_1, Reg(0), Reg(1));
   AddMove(gap_1, Reg(1), Reg(0));
 
   StartBlock();
   EndBlock(Last());
 
+  auto last = LastInstruction();
+
   Optimize();
 
   CHECK(gap_0->AreMovesRedundant());
   CHECK(gap_1->AreMovesRedundant());
-  auto move = LastInstruction()->parallel_moves()[0];
+  auto move = last->parallel_moves()[0];
   CHECK_EQ(2, NonRedundantSize(move));
   CHECK(Contains(move, Reg(0), Reg(1)));
   CHECK(Contains(move, Reg(1), Reg(0)));
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8