This patch fixes debugging of single threaded apps on Linux. 
It also adds some asserts and additional logging support.

from dawn@burble.org

llvm-svn: 142384
diff --git a/lldb/source/Plugins/Process/Linux/ProcessLinux.h b/lldb/source/Plugins/Process/Linux/ProcessLinux.h
index 713e8ba..1a98443 100644
--- a/lldb/source/Plugins/Process/Linux/ProcessLinux.h
+++ b/lldb/source/Plugins/Process/Linux/ProcessLinux.h
@@ -177,7 +177,8 @@
     /// Registers the given message with this process.
     void SendMessage(const ProcessMessage &message);
 
-    ProcessMonitor &GetMonitor() { return *m_monitor; }
+    ProcessMonitor &
+    GetMonitor() { assert(m_monitor); return *m_monitor; }
 
     lldb_private::UnixSignals &
     GetUnixSignals();