Revert of Replace all remaining Oddball checks with new function

src/runtime/runtime-strings.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/runtime/runtime-utils.h"
 
 #include "src/arguments.h"
 #include "src/regexp/jsregexp-inl.h"
 #include "src/string-builder.h"
 #include "src/string-search.h"
@@ skipping 1038 matching lines @@
   }
 
   Handle<SeqString> result;  // Same length as input.
   if (s->IsOneByteRepresentation()) {
     result = isolate->factory()->NewRawOneByteString(length).ToHandleChecked();
   } else {
     result = isolate->factory()->NewRawTwoByteString(length).ToHandleChecked();
   }
 
   Object* answer = ConvertCaseHelper(isolate, *s, *result, length, mapping);
-  if (answer->IsException(isolate) || answer->IsString()) return answer;
+  if (answer->IsException() || answer->IsString()) return answer;
 
   DCHECK(answer->IsSmi());
   length = Smi::cast(answer)->value();
   if (s->IsOneByteRepresentation() && length > 0) {
     ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
         isolate, result, isolate->factory()->NewRawOneByteString(length));
   } else {
     if (length < 0) length = -length;
     ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
         isolate, result, isolate->factory()->NewRawTwoByteString(length));
@@ skipping 136 matching lines @@
   SealHandleScope shs(isolate);
   DCHECK(args.length() == 2);
   if (!args[0]->IsString()) return isolate->heap()->undefined_value();
   if (!args[1]->IsNumber()) return isolate->heap()->undefined_value();
   if (std::isinf(args.number_at(1))) return isolate->heap()->nan_value();
   return __RT_impl_Runtime_StringCharCodeAtRT(args, isolate);
 }
 
 }  // namespace internal
 }  // namespace v8