[strong] Remove all remainders of strong mode

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 237 matching lines @@
 define kUseAsm = 0;
 define kBreakIterator = 1;
 define kLegacyConst = 2;
 define kMarkDequeOverflow = 3;
 define kStoreBufferOverflow = 4;
 define kSlotsBufferOverflow = 5;
 define kObjectObserve = 6;
 define kForcedGC = 7;
 define kSloppyMode = 8;
 define kStrictMode = 9;
-define kStrongMode = 10;
 define kRegExpPrototypeStickyGetter = 11;
 define kRegExpPrototypeToString = 12;
 define kRegExpPrototypeUnicodeGetter = 13;
 define kIntlV8Parse = 14;
 define kIntlPattern = 15;
 define kIntlResolved = 16;
 define kPromiseChain = 17;
 define kPromiseAccept = 18;
 define kPromiseDefer = 19;