Thread hardening part 3. Now lldb_private::Thread objects have std::weak_ptr
objects for the backlink to the lldb_private::Process. The issues we were
running into before was someone was holding onto a shared pointer to a 
lldb_private::Thread for too long, and the lldb_private::Process parent object
would get destroyed and the lldb_private::Thread had a "Process &m_process"
member which would just treat whatever memory that used to be a Process as a
valid Process. This was mostly happening for lldb_private::StackFrame objects
that had a member like "Thread &m_thread". So this completes the internal
strong/weak changes.

Documented the ExecutionContext and ExecutionContextRef classes so that our
LLDB developers can understand when and where to use ExecutionContext and 
ExecutionContextRef objects.



git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@151009 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/source/Plugins/Process/gdb-remote/ThreadGDBRemote.h b/source/Plugins/Process/gdb-remote/ThreadGDBRemote.h
index 09f8684..3eb6295 100644
--- a/source/Plugins/Process/gdb-remote/ThreadGDBRemote.h
+++ b/source/Plugins/Process/gdb-remote/ThreadGDBRemote.h
@@ -21,7 +21,7 @@
 class ThreadGDBRemote : public lldb_private::Thread
 {
 public:
-    ThreadGDBRemote (ProcessGDBRemote &process, lldb::tid_t tid);
+    ThreadGDBRemote (const lldb::ProcessSP &process_sp, lldb::tid_t tid);
 
     virtual
     ~ThreadGDBRemote ();
@@ -47,18 +47,6 @@
     virtual void
     ClearStackFrames ();
 
-    ProcessGDBRemote &
-    GetGDBProcess ()
-    {
-        return (ProcessGDBRemote &)m_process;
-    }
-
-    const ProcessGDBRemote &
-    GetGDBProcess () const
-    {
-        return (ProcessGDBRemote &)m_process;
-    }
-
     void
     Dump (lldb_private::Log *log, uint32_t index);