Save out a correct lookup table if a lookup table entry is stale (it contains
an out-of-date external decls list). This happens if we declare some names,
force the lookup table for the decl context to be built, import a module that
adds more decls for the name, then write out our module without looking up the
name.

llvm-svn: 204694
diff --git a/clang/test/Modules/namespaces.cpp b/clang/test/Modules/namespaces.cpp
index 003c7d3..c27c5f0 100644
--- a/clang/test/Modules/namespaces.cpp
+++ b/clang/test/Modules/namespaces.cpp
@@ -36,6 +36,9 @@
   double &dr3 = global(1.0);
   double &dr4 = ::global2(1.0);
   double &dr5 = LookupBeforeImport::f(1.0);
+
+  struct AddAndReexportBeforeImport::S s;
+  int k = AddAndReexportBeforeImport::S;
 }
 
 // Test namespaces merged without a common first declaration.