Check if a loaded module is a swift module

Author: elsh

lib/Sema/TypeCheckDeclPrimary.cpp

@@ -1961,7 +1961,8 @@ class DeclChecker : public DeclVisitor<DeclChecker> {
     (void)ID->getDecls();
 
     auto target = ID->getModule();
-    if (target->isNonUserModule() && // target module is in distributed SDK
+    if (!target->isNonSwiftModule() && // target is a Swift module
+        target->isNonUserModule() && // target module is in distributed SDK
         !getASTContext().LangOpts.PackageName.empty() &&
         getASTContext().LangOpts.PackageName == target->getPackageName().str()) {
       // If reached here, a binary module (.swiftmodule) instead of interface of the