[don't duplicate foreign declarations in typechecker
John Meacham <john@repetae.net>**20060816045756] hunk ./FrontEnd/Tc/Main.hs 565
+-- foreign decls are accumulated by tiExpl
hunk ./FrontEnd/Tc/Main.hs 570
-    return [fd]
+    return []
hunk ./FrontEnd/Tc/Main.hs 576
-    return [fd]
+    return []