Implement QPassSignals GDB package in lldb-server

Summary: QPassSignals package allows lldb client to tell lldb-server to ignore certain types of signals and re-inject them back to inferior without stopping execution.

Reviewers: jmajors, labath

Subscribers: danalbert, srhines, emaste, lldb-commits

Tags: #lldb

Differential Revision: https://reviews.llvm.org/D30286
Author: Eugene Zemtsov <ezemtsov@google.com>

llvm-svn: 296101

lldb/source/Utility/StringExtractorGDBRemote.cpp

@@ -91,6 +91,10 @@ StringExtractorGDBRemote::GetServerPacketType() const {
         return eServerPacketType_QEnvironmentHexEncoded;
       break;
 
+    case 'P':
+      if (PACKET_STARTS_WITH("QPassSignals:"))
+        return eServerPacketType_QPassSignals;
+
     case 'S':
       if (PACKET_MATCHES("QStartNoAckMode"))
         return eServerPacketType_QStartNoAckMode;