For DR712: store on a DeclRefExpr whether it constitutes an odr-use.

Begin restructuring to support the forms of non-odr-use reference
permitted by DR712.

llvm-svn: 363086
diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index e0a9da5..c4ae3b8 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -6189,7 +6189,7 @@
   auto *ToE = DeclRefExpr::Create(
       Importer.getToContext(), ToQualifierLoc, ToTemplateKeywordLoc, ToDecl,
       E->refersToEnclosingVariableOrCapture(), ToLocation, ToType,
-      E->getValueKind(), ToFoundD, ToResInfo);
+      E->getValueKind(), ToFoundD, ToResInfo, E->isNonOdrUse());
   if (E->hadMultipleCandidates())
     ToE->setHadMultipleCandidates(true);
   return ToE;