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
diff --git a/lldb/source/API/SBPlatform.cpp b/lldb/source/API/SBPlatform.cpp
index 5662f36..97ffcf1 100644
--- a/lldb/source/API/SBPlatform.cpp
+++ b/lldb/source/API/SBPlatform.cpp
@@ -11,6 +11,7 @@
 #include "lldb/API/SBError.h"
 #include "lldb/API/SBFileSpec.h"
 #include "lldb/API/SBLaunchInfo.h"
+#include "lldb/API/SBUnixSignals.h"
 #include "lldb/Core/ArchSpec.h"
 #include "lldb/Core/Error.h"
 #include "lldb/Host/File.h"
@@ -638,3 +639,11 @@
     
 }
 
+SBUnixSignals
+SBPlatform::GetUnixSignals() const
+{
+    if (auto platform_sp = GetSP())
+        return SBUnixSignals{platform_sp};
+
+    return {};
+}