Refactor Unix signals.

Summary:
- Consolidate Unix signals selection in UnixSignals.
- Make Unix signals available from platform.
- Add jSignalsInfo packet to retrieve Unix signals from remote platform.
- Get a copy of the platform signal for each remote process.
- Update SB API for signals.
- Update signal utility in test suite.

Reviewers: ovyalov, clayborg

Subscribers: chaoren, jingham, labath, emaste, tberghammer, lldb-commits

Differential Revision: http://reviews.llvm.org/D11094

llvm-svn: 242101

lldb/source/API/SBThread.cpp

@@ -392,7 +392,7 @@ SBThread::GetStopDescription (char *dst, size_t dst_len)
 
                     case eStopReasonSignal:
                         {
-                            stop_desc = exe_ctx.GetProcessPtr()->GetUnixSignals ().GetSignalAsCString (stop_info_sp->GetValue());
+                            stop_desc = exe_ctx.GetProcessPtr()->GetUnixSignals()->GetSignalAsCString(stop_info_sp->GetValue());
                             if (stop_desc == NULL || stop_desc[0] == '\0')
                             {
                                 static char signal_desc[] = "signal";