Remove unnecessary checks and runtime calls from ToLength

src/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 56 matching lines @@
 define kMinYear  = -1000000;
 define kMaxYear  = 1000000;
 define kMinMonth = -10000000;
 define kMaxMonth = 10000000;
 
 # Safe maximum number of arguments to push to stack, when multiplied by
 # pointer size. Used by Function.prototype.apply(), Reflect.apply() and
 # Reflect.construct().
 define kSafeArgumentsLength = 0x800000;
 
+# 2^53 - 1
+define kMaxSafeInteger = 9007199254740991;
+
 # Strict mode flags for passing to %SetProperty
 define kSloppyMode = 0;
 define kStrictMode = 1;
 
 # Native cache ids.
 define STRING_TO_REGEXP_CACHE_ID = 0;
 
 # Type query macros.
 #
 # Note: We have special support for typeof(foo) === 'bar' in the compiler.
@@ skipping 214 matching lines @@
 define NOT_FOUND = -1;
 
 # Check whether debug is active.
 define DEBUG_IS_ACTIVE = (%_DebugIsActive() != 0);
 macro DEBUG_IS_STEPPING(function) = (%_DebugIsActive() != 0 && %DebugCallbackSupportsStepping(function));
 macro DEBUG_PREPARE_STEP_IN_IF_STEPPING(function) = if (DEBUG_IS_STEPPING(function)) %DebugPrepareStepInIfStepping(function);
 
 # SharedFlag equivalents
 define kNotShared = false;
 define kShared = true;