PR19411: Walk lexical parents, not semantic parents, when determining whether a
DeclContext is (lexically) within a C language linkage specification.

llvm-svn: 206204
diff --git a/clang/lib/AST/DeclBase.cpp b/clang/lib/AST/DeclBase.cpp
index 1de1fe2..c12f53c6 100644
--- a/clang/lib/AST/DeclBase.cpp
+++ b/clang/lib/AST/DeclBase.cpp
@@ -837,7 +837,7 @@
   while (DC->getDeclKind() != Decl::TranslationUnit) {
     if (DC->getDeclKind() == Decl::LinkageSpec)
       return cast<LinkageSpecDecl>(DC)->getLanguage() == ID;
-    DC = DC->getParent();
+    DC = DC->getLexicalParent();
   }
   return false;
 }