Introduce ENABLE_LATIN_1 compile flag

src/x64/code-stubs-x64.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 4516 matching lines @@
   __ Abort("Unexpected fallthrough from CharCodeAt slow case");
 }
 
 
 // -------------------------------------------------------------------------
 // StringCharFromCodeGenerator
 
 void StringCharFromCodeGenerator::GenerateFast(MacroAssembler* masm) {
   // Fast case of Heap::LookupSingleCharacterStringFromCode.
   __ JumpIfNotSmi(code_, &slow_case_);
-  __ SmiCompare(code_, Smi::FromInt(String::kMaxAsciiCharCode));
+  __ SmiCompare(code_, Smi::FromInt(String::kMaxOneByteCharCode));
   __ j(above, &slow_case_);
 
   __ LoadRoot(result_, Heap::kSingleCharacterStringCacheRootIndex);
   SmiIndex index = masm->SmiToIndex(kScratchRegister, code_, kPointerSizeLog2);
   __ movq(result_, FieldOperand(result_, index.reg, index.scale,
                                 FixedArray::kHeaderSize));
   __ CompareRoot(result_, Heap::kUndefinedValueRootIndex);
   __ j(equal, &slow_case_);
   __ bind(&exit_);
 }
@@ skipping 1936 matching lines @@
 #endif
 
   __ Ret();
 }
 
 #undef __
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_X64