Change Target & Process so they can really be initialized with an invalid architecture. 
Arrange that this then gets properly set on attach, or when a "file" is set.
Add a completer for "process attach -n".

Caveats: there isn't currently a way to handle multiple processes with the same name.  That
will have to wait on a way to pass annotations along with the completion strings.

llvm-svn: 110624
diff --git a/lldb/source/Target/StopInfo.cpp b/lldb/source/Target/StopInfo.cpp
index 9d48e81..54fc6da 100644
--- a/lldb/source/Target/StopInfo.cpp
+++ b/lldb/source/Target/StopInfo.cpp
@@ -79,7 +79,7 @@
                                                   &m_thread.GetProcess(), 
                                                   &m_thread, 
                                                   m_thread.GetStackFrameAtIndex(0).get(),
-                                                  false);
+                                                  true);
                 
                 m_should_stop = bp_site_sp->ShouldStop (&context);
             }