[modules] Don't make out-of-line member specializations of an instantiated
class template specialization visible just because the class template
specialization's definition is visible.

llvm-svn: 241182
diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index 70bd16f..d20451d 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -236,6 +236,7 @@
   } else {
     getMultipleDC()->LexicalDC = DC;
   }
+  Hidden = cast<Decl>(DC)->Hidden;
 }
 
 void Decl::setDeclContextsImpl(DeclContext *SemaDC, DeclContext *LexicalDC,