[macros] Implement NUMBER_IS_NAN in terms of strict equality.

src/js/macros.py

 # Copyright 2006-2009 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 64 matching lines @@
 macro IS_RECEIVER(arg) = (%_IsJSReceiver(arg));
 
 # Macro for ES queries of the type: "IsCallable(O)"
 macro IS_CALLABLE(arg) = (typeof(arg) === 'function');
 
 # Macro for ES6 CheckObjectCoercible
 # Will throw a TypeError of the form "[functionName] called on null or undefined".
 macro CHECK_OBJECT_COERCIBLE(arg, functionName) = if (IS_NULL(%IS_VAR(arg)) || IS_UNDEFINED(arg)) throw %make_type_error(kCalledOnNullOrUndefined, functionName);
 
 # Inline macros. Use %IS_VAR to make sure arg is evaluated only once.
-macro NUMBER_IS_NAN(arg) = (!%_IsSmi(%IS_VAR(arg)) && !(arg == arg));
+macro NUMBER_IS_NAN(arg) = (%IS_VAR(arg) !== arg);
 macro NUMBER_IS_FINITE(arg) = (%_IsSmi(%IS_VAR(arg)) || ((arg == arg) && (arg != 1/0) && (arg != -1/0)));
 macro TO_BOOLEAN(arg) = (!!(arg));
 macro TO_INTEGER(arg) = (%_ToInteger(arg));
 macro TO_INT32(arg) = ((arg) | 0);
 macro TO_UINT32(arg) = ((arg) >>> 0);
 macro INVERT_NEG_ZERO(arg) = ((arg) + 0);
 macro TO_LENGTH(arg) = (%_ToLength(arg));
 macro TO_STRING(arg) = (%_ToString(arg));
 macro TO_NUMBER(arg) = (%_ToNumber(arg));
 macro TO_OBJECT(arg) = (%_ToObject(arg));
@@ skipping 92 matching lines @@
 define kSloppyModeBlockScopedFunctionRedefinition = 22;
 define kForInInitializer = 23;
 define kArrayProtectorDirtied = 24;
 define kArraySpeciesModified = 25;
 define kArrayPrototypeConstructorModified = 26;
 define kArrayInstanceProtoModified = 27;
 define kArrayInstanceConstructorModified = 28;
 define kLegacyFunctionDeclaration = 29;
 define kRegExpPrototypeSourceGetter = 30;
 define kRegExpPrototypeOldFlagGetter = 31;