Fix three ~Isolate() related memory leaks

src/isolate.cc

 // Copyright 2011 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 1317 matching lines @@
   if (list_ != NULL) list_->prev_ = data;
   data->next_ = list_;
   list_ = data;
 }
 
 
 void Isolate::ThreadDataTable::Remove(PerIsolateThreadData* data) {
   if (list_ == data) list_ = data->next_;
   if (data->next_ != NULL) data->next_->prev_ = data->prev_;
   if (data->prev_ != NULL) data->prev_->next_ = data->next_;
+  delete data;
 }
 
 
 void Isolate::ThreadDataTable::Remove(Isolate* isolate,
                                       ThreadId thread_id) {
   PerIsolateThreadData* data = Lookup(isolate, thread_id);
   if (data != NULL) {
     Remove(data);
   }
 }
@@ skipping 181 matching lines @@
   Thread::SetThreadLocal(per_isolate_thread_data_key_, data);
 }
 
 
 Isolate::~Isolate() {
   TRACE_ISOLATE(destructor);
 
   // Has to be called while counters_ are still alive.
   zone_.DeleteKeptSegment();
 
+  delete assembler_spare_buffer_;
+  assembler_spare_buffer_ = NULL;
+
   delete unicode_cache_;
   unicode_cache_ = NULL;
 
   delete regexp_stack_;
   regexp_stack_ = NULL;
 
   delete ast_sentinels_;
   ast_sentinels_ = NULL;
 
   delete descriptor_lookup_cache_;
@@ skipping 322 matching lines @@
 
 #ifdef DEBUG
 #define ISOLATE_FIELD_OFFSET(type, name, ignored)                       \
 const intptr_t Isolate::name##_debug_offset_ = OFFSET_OF(Isolate, name##_);
 ISOLATE_INIT_LIST(ISOLATE_FIELD_OFFSET)
 ISOLATE_INIT_ARRAY_LIST(ISOLATE_FIELD_OFFSET)
 #undef ISOLATE_FIELD_OFFSET
 #endif
 
 } }  // namespace v8::internal