Given Decl::isUsed() a flag indicating when to consider the "used"
attribute as part of the calculation. Sema::MarkDeclReferenced(), and
a few other places, want only to consider the "used" bit to determine,
e.g, whether to perform template instantiation. Fixes a linkage issue
with Boost.Serialization.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@106252 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index b7059e5..1b28579 100644
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -361,7 +361,9 @@
     Var->setLexicalDeclContext(D->getLexicalDeclContext());
 
   Var->setAccess(D->getAccess());
-  Var->setUsed(D->isUsed());
+  
+  if (!D->isStaticDataMember())
+    Var->setUsed(D->isUsed(false));
   
   // FIXME: In theory, we could have a previous declaration for variables that
   // are not static data members.