Fix the storage class of method instantiations.

We keep the "as written" storage class, but that is a fuzzy concept for
instantiations. With this patch instantiations of methods of class templates
now get a storage class that is based on the semantics of isStatic(). With this
can simplify isStatic() itself.

llvm-svn: 179521
diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 868369e..2dbfeec 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -1530,10 +1530,10 @@
                                        Conversion->isConstexpr(),
                                        Conversion->getLocEnd());
   } else {
+    StorageClass SC = D->isStatic() ? SC_Static : SC_None;
     Method = CXXMethodDecl::Create(SemaRef.Context, Record,
                                    StartLoc, NameInfo, T, TInfo,
-                                   D->getStorageClass(),
-                                   D->isInlineSpecified(),
+                                   SC, D->isInlineSpecified(),
                                    D->isConstexpr(), D->getLocEnd());
   }