Update tests to use std::isnan instead of isnan

test/cctest/test-heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 181 matching lines @@
 
   maybe_value = heap->NumberFromUint32(static_cast<uint32_t>(1) << 31);
   value = maybe_value->ToObjectChecked();
   CHECK(value->IsHeapNumber());
   CHECK(value->IsNumber());
   CHECK_EQ(static_cast<double>(static_cast<uint32_t>(1) << 31),
            value->Number());
 
   // nan oddball checks
   CHECK(heap->nan_value()->IsNumber());
-  CHECK(isnan(heap->nan_value()->Number()));
+  CHECK(std::isnan(heap->nan_value()->Number()));
 
   Handle<String> s = FACTORY->NewStringFromAscii(CStrVector("fisk hest "));
   CHECK(s->IsString());
   CHECK_EQ(10, s->length());
 
   String* object_string = String::cast(heap->Object_string());
   CHECK(
       Isolate::Current()->context()->global_object()->HasLocalProperty(
           object_string));
 
@@ skipping 2846 matching lines @@
   }
   // An entire block of handles has been filled.
   // Next handle would require a new block.
   ASSERT(data->next == data->limit);
 
   DeferredHandleScope deferred(isolate);
   DummyVisitor visitor;
   isolate->handle_scope_implementer()->Iterate(&visitor);
   deferred.Detach();
 }