include "thread-pcs" info in stop reply

[andrurogerz]

DS2 does not implement the thread-pcs stop reply extension documented here. The TestGdbRemoteThreadsInStopReply.test_stop_reply_contains_thread_pcs_llgs lldb test case fails as a result.

From the lldb packet documentation:

thread-pcs - comma-sep-base16 - A list of pc values for all threads that currently exist in the process, including the thread that this T packet is reporting as stopped. This key-value pair will only be emitted when the threads key is already included in the T packet. The pc values correspond to the threads reported in the threads list. The number of pcs in the thread-pcs list will be the same as the number of threads in the threads list. lldb may request that this be included in the T packet via the QListThreadsInStopReply packet earlier in the debug session.

Example:
thread-pcs:dec14,2cf872b0,2cf8681c,2d02d68c,2cf716a8;