Finish converting decls over to the new invalid decl API.

Also removed an old FIXME (FIXME: "auto func();" passes through...).


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@41555 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Sema/SemaExpr.cpp b/Sema/SemaExpr.cpp
index bea6e99..eb7daf1 100644
--- a/Sema/SemaExpr.cpp
+++ b/Sema/SemaExpr.cpp
@@ -76,7 +76,7 @@
   }
   if (ValueDecl *VD = dyn_cast<ValueDecl>(D)) {
     // Only create DeclRefExpr's for valid Decl's.
-    if (VD->getInvalidDecl())
+    if (VD->isInvalidDecl())
       return true;
     return new DeclRefExpr(VD, VD->getType(), Loc);
   }