silence has_changed_character may be used uninitialized warning

src/runtime.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 6483 matching lines @@
   // NOTE: This assumes that the upper/lower case of an ASCII
   // character is also ASCII.  This is currently the case, but it
   // might break in the future if we implement more context and locale
   // dependent upper/lower conversions.
   if (s->IsSeqOneByteString()) {
     Object* o;
     { MaybeObject* maybe_o = isolate->heap()->AllocateRawOneByteString(length);
       if (!maybe_o->ToObject(&o)) return maybe_o;
     }
     SeqOneByteString* result = SeqOneByteString::cast(o);
-    bool has_changed_character;
+    bool has_changed_character = false;
     bool is_ascii = FastAsciiConvert<Converter>(
         reinterpret_cast<char*>(result->GetChars()),
         reinterpret_cast<char*>(SeqOneByteString::cast(s)->GetChars()),
         length,
         &has_changed_character);
     // If not ASCII, we discard the result and take the 2 byte path.
     if (is_ascii) {
       return has_changed_character ? result : s;
     }
   }
@@ skipping 8387 matching lines @@
     // Handle last resort GC and make sure to allow future allocations
     // to grow the heap without causing GCs (if possible).
     isolate->counters()->gc_last_resort_from_js()->Increment();
     isolate->heap()->CollectAllGarbage(Heap::kNoGCFlags,
                                        "Runtime::PerformGC");
   }
 }
 
 
 } }  // namespace v8::internal