* runtime_sigprof.cpp (struct CTraceStruct): New fields. To record thread
times.
(struct ThreadInfo): New field. To record thread time.
(CTraceStruct::CTraceStruct): Delete the initialization of min_end_time_.
We don't care it, so don't waste time.
(MyHandler): Update time & thread time accordingly.
(struct Record): New fields. Similar.
(RecordThis): Update. Similar.
(DoWriteRecursive): Write thread times.
(__start_ctrace__): Delete useless updates.
(__end_ctrace__): Update thread mini end time.