When supplying memory to expedite the unwinds in the T packet,

include two stack frames worth of unwind information instead of
just one -- the unwinder is trying to fetch two stack frames in
more instances now and we're sending extra memory reads resulting
in a performance degredation while stepping.

llvm-svn: 255417

lldb/tools/debugserver/source/RNBRemote.cpp

@@ -2812,7 +2812,7 @@ RNBRemote::SendStopReplyPacketForThread (nub_thread_t tid)
         // Add expedited stack memory so stack backtracing doesn't need to read anything from the
         // frame pointer chain.
         StackMemoryMap stack_mmap;
-        ReadStackMemory (pid, tid, stack_mmap, 1);
+        ReadStackMemory (pid, tid, stack_mmap, 2);
         if (!stack_mmap.empty())
         {
             for (const auto &stack_memory : stack_mmap)