IRGen: compute locality for type declarations

We previously did not properly compute the link info for type
declarations. This becomes a problem for metadata accessors which are
canonically remote (e.g. the type metadata accessor for `NSError`). This
fixes the incorrect DLLStorage that was being attributed to these
functions.

Author: compnerd

lib/IRGen/GenDecl.cpp

@@ -2377,6 +2377,12 @@ LinkInfo LinkInfo::get(const UniversalLinkageInfo &linkInfo,
     // types to be referenced directly.
     if (const auto *MD = entity.getSILFunction()->getParentModule())
       isKnownLocal = MD == swiftModule || MD->isStaticLibrary();
+  } else if (entity.isTypeKind()) {
+    if (NominalTypeDecl *NTD = entity.getType().getAnyNominal()) {
+      const ModuleDecl *MD =
+          NTD->getDecl()->getDeclContext()->getParentModule();
+      isKnownLocal = MD == swiftModule || MD->isStaticLibrary();
+    }
   }
 
   bool weakImported = entity.isWeakImported(swiftModule);