Currently it errors when loading a module built from interface if it has package-name.

This disallows building an interface file that imports such module which should be allowed
since interface does not contain package symbols unless usableFromInline or inlinable.
This change limits erroring only when building a .swift file.

Resolves rdar://108633068

lib/Serialization/SerializedModuleLoader.cpp

@@ -804,15 +804,6 @@ LoadedFile *SerializedModuleLoaderBase::loadAST(
     if (loadedModuleFile->isConcurrencyChecked())
       M.setIsConcurrencyChecked();
     if (!loadedModuleFile->getModulePackageName().empty()) {
-      if (loadedModuleFile->isBuiltFromInterface() &&
-          loadedModuleFile->getModulePackageName().str() == Ctx.LangOpts.PackageName) {
-        Ctx.Diags.diagnose(SourceLoc(),
-                           diag::in_package_module_not_compiled_from_source,
-                           M.getBaseIdentifier(),
-                           Ctx.LangOpts.PackageName,
-                           loadedModuleFile->getModuleSourceFilename()
-                           );
-      }
       M.setPackageName(Ctx.getIdentifier(loadedModuleFile->getModulePackageName()));
     }
     M.setUserModuleVersion(loadedModuleFile->getUserModuleVersion());