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

src/compiler/node-cache.h

 // 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.
 
 #ifndef V8_COMPILER_NODE_CACHE_H_
 #define V8_COMPILER_NODE_CACHE_H_
 
 #include "src/base/functional.h"
 #include "src/base/macros.h"
 
@@ skipping 17 matching lines @@
 template <typename Key, typename Hash = base::hash<Key>,
           typename Pred = std::equal_to<Key> >
 class NodeCache final {
  public:
   explicit NodeCache(unsigned max = 256)
       : entries_(nullptr), size_(0), max_(max) {}
   ~NodeCache() {}
 
   // Search for node associated with {key} and return a pointer to a memory
   // location in this cache that stores an entry for the key. If the location
-  // returned by this method contains a non-NULL node, the caller can use that
+  // returned by this method contains a non-nullptr node, the caller can use
+  // that
   // node. Otherwise it is the responsibility of the caller to fill the entry
   // with a new node.
   // Note that a previous cache entry may be overwritten if the cache becomes
   // too full or encounters too many hash collisions.
   Node** Find(Zone* zone, Key key);
 
   // Appends all nodes from this cache to {nodes}.
   void GetCachedNodes(ZoneVector<Node*>* nodes);
 
  private:
@@ skipping 17 matching lines @@
 typedef Int32NodeCache IntPtrNodeCache;
 #else
 typedef Int64NodeCache IntPtrNodeCache;
 #endif
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_NODE_CACHE_H_