[gcjx] Patch: FYI: fix type variable signatures

[Tom Tromey]

I'm checking this in on the gcjx branch.

This fixes a buglet when generating a type variable signature.
If there was no bound we created an entry consisting of just ':'.
However that is not parseable.  Instead we must emit a bound of
Object in this case.

Tom

Index: ChangeLog
from  Tom Tromey  <tromey@redhat.com>
	* model/typevar.cc (get_formal_signature): Special-case empty
	bounds.

Index: model/typevar.cc
===================================================================
--- model/typevar.cc	(revision 107604)
+++ model/typevar.cc	(working copy)
@@ -162,7 +162,7 @@
     }
   // Handle the case where there were no bounds at all.
   if (bounds.empty ())
-    result += ":";
+    result += ":" + global->get_compiler ()->java_lang_Object ()->get_signature ();
   return result;
 }