[turbofan] Build s/NULL/nullptr/g and CHECK(x != nullptr) to CHECK_NOT_NULL(x).

src/compiler/code-generator.cc

 // Copyright 2013 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/code-generator.h"
 
 #include "src/address-map.h"
 #include "src/compiler/code-generator-impl.h"
 #include "src/compiler/linkage.h"
 #include "src/compiler/pipeline.h"
@@ skipping 23 matching lines @@
 
 CodeGenerator::CodeGenerator(Frame* frame, Linkage* linkage,
                              InstructionSequence* code, CompilationInfo* info)
     : frame_access_state_(new (code->zone()) FrameAccessState(frame)),
       linkage_(linkage),
       code_(code),
       info_(info),
       labels_(zone()->NewArray<Label>(code->InstructionBlockCount())),
       current_block_(RpoNumber::Invalid()),
       current_source_position_(SourcePosition::Unknown()),
-      masm_(info->isolate(), NULL, 0, CodeObjectRequired::kYes),
+      masm_(info->isolate(), nullptr, 0, CodeObjectRequired::kYes),
       resolver_(this),
       safepoints_(code->zone()),
       handlers_(code->zone()),
       deoptimization_states_(code->zone()),
       deoptimization_literals_(code->zone()),
       inlined_function_count_(0),
       translations_(code->zone()),
       last_lazy_deopt_pc_(0),
       jump_tables_(nullptr),
       ools_(nullptr),
@@ skipping 673 matching lines @@
     : frame_(gen->frame()), masm_(gen->masm()), next_(gen->ools_) {
   gen->ools_ = this;
 }
 
 
 OutOfLineCode::~OutOfLineCode() {}
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8