NCGenerics: add workaround for rev. condfail

resolves rdar://130424971

Author: kavon

lib/Sema/TypeCheckGeneric.cpp

@@ -788,6 +788,14 @@ GenericSignatureRequest::evaluate(Evaluator &evaluator,
     // to invertible protocols. This forces people to write out the conditions.
     inferInvertibleReqs = !ext->isAddingConformanceToInvertible();
 
+    // FIXME: to workaround a reverse condfail, always infer the requirements if
+    //  the extension is in a swiftinterface file. This is temporary and should
+    //  be removed soon. (rdar://130424971)
+    if (auto *sf = ext->getOutermostParentSourceFile()) {
+      if (sf->Kind == SourceFileKind::Interface)
+        inferInvertibleReqs = true;
+    }
+
     collectAdditionalExtensionRequirements(ext->getExtendedType(), extraReqs);
 
     auto *extendedNominal = ext->getExtendedNominal();

test/ModuleInterface/noncopyable_generics_interface_extensions.swift

@@ -0,0 +1,32 @@
+// RUN: %empty-directory(%t)
+// RUN: split-file %s %t
+// RUN: %target-swift-typecheck-module-from-interface(%t/bug.swiftinterface) -I %t
+
+//--- bug.swiftinterface
+
+// swift-interface-format-version: 1.0
+// swift-compiler-version: Apple Swift version 6.0 effective-5.10 (swiftlang-6.0.0.4.52 clang-1600.0.21.1.3)
+// swift-module-flags: -target arm64-apple-macosx15.0 -enable-objc-interop -enable-library-evolution -module-name bug
+import Swift
+import _Concurrency
+import _StringProcessing
+import _SwiftConcurrencyShims
+#if compiler(>=5.3) && $NoncopyableGenerics
+public enum Maybe<Wrapped> : ~Swift.Copyable where Wrapped : ~Copyable {
+  case just(Wrapped)
+  case none
+}
+#else
+public enum Maybe<Wrapped> {
+  case just(Wrapped)
+  case none
+}
+#endif
+#if compiler(>=5.3) && $NoncopyableGenerics
+extension bug.Maybe : Swift.Copyable {
+}
+#else
+extension bug.Maybe {
+}
+#endif
+