Add jThreadsInfo support to lldb-server

Summary:
This commit adds initial support for the jThreadsInfo packet to lldb-server. The current
implementation does not expedite inferior memory.  I have also added a description of the new
packet to our protocol documentation (mostly taken from Greg's earlier commit message).

Reviewers: clayborg, ovyalov, tberghammer

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D11187

llvm-svn: 242402
diff --git a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
index dbd68b4..94dac0c 100644
--- a/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
+++ b/lldb/source/Plugins/Process/gdb-remote/ProcessGDBRemote.cpp
@@ -1397,6 +1397,7 @@
     m_continue_C_tids.clear();
     m_continue_s_tids.clear();
     m_continue_S_tids.clear();
+    m_threads_info_sp.reset();
     return Error();
 }
 
@@ -2094,6 +2095,7 @@
     static ConstString g_key_address("address");
     static ConstString g_key_bytes("bytes");
     static ConstString g_key_description("description");
+    static ConstString g_key_signal("signal");
 
     // Stop with signal and thread info
     lldb::tid_t tid = LLDB_INVALID_THREAD_ID;
@@ -2238,6 +2240,8 @@
             }
 
         }
+        else if (key == g_key_signal)
+            signo = object->GetIntegerValue(LLDB_INVALID_SIGNAL_NUMBER);
         return true; // Keep iterating through all dictionary key/value pairs
     });