[NCGenerics] hack for module mismatch

lib/Serialization/ModuleFileSharedCore.cpp

@@ -425,6 +425,12 @@ static ValidationInfo validateControlBlock(
       break;
     }
     case control_block::HAS_NONCOPYABLE_GENERICS: {
+      // FIXME: temporary hack until the stdlib is actually building.
+      // This skips over the module mismatch error if the stdlib wasn't built
+      // with noncopyable generics, so that tests may still run in CI.
+      if (!SWIFT_ENABLE_EXPERIMENTAL_NONCOPYABLE_GENERICS)
+        break;
+
       auto hasNoncopyableGenerics = scratch[0];
       if (requiresNoncopyableGenerics && !hasNoncopyableGenerics)
         result.status = Status::NotUsingNoncopyableGenerics;