Add a call to "sync" a thread state before checkpointing registers in preparation for 
calling functions.  This is necessary on Mac OS X, since bad things can happen if you set
the registers of a thread that's sitting in a kernel trap.

<rdar://problem/11145013>

llvm-svn: 160756
diff --git a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
index eee3aa5..adfec5b 100644
--- a/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
+++ b/lldb/source/Plugins/Process/gdb-remote/GDBRemoteCommunicationClient.h
@@ -224,6 +224,9 @@
     bool
     GetVAttachOrWaitSupported ();
     
+    bool
+    GetSyncThreadStateSupported();
+    
     void
     ResetDiscoverableSettings();
 
@@ -369,6 +372,7 @@
     lldb_private::LazyBool m_supports_watchpoint_support_info;
     lldb_private::LazyBool m_watchpoints_trigger_after_instruction;
     lldb_private::LazyBool m_attach_or_wait_reply;
+    lldb_private::LazyBool m_prepare_for_reg_writing_reply;
     
     bool
         m_supports_qProcessInfoPID:1,