IRGen: Always emit class stubs for classes with resilient ancestry

This logic is no longer guarded by a flag. Sema will still emit certain
diagnostics if the flag is not specified though.

Progress on <rdar://problem/49090631>.

Author: slavapestov

lib/IRGen/GenClass.cpp

@@ -1211,7 +1211,6 @@ namespace {
       // hierarchy crosses resilience domains, we use a
       // slightly different query here.
       if (theClass->checkAncestry(AncestryFlags::ResilientOther)) {
-        assert(IGM.Context.LangOpts.EnableObjCResilientClassStubs);
         return IGM.getAddrOfObjCResilientClassStub(theClass, NotForDefinition,
                                              TypeMetadataAddress::AddressPoint);
       }
@@ -2072,9 +2071,7 @@ static llvm::Function *emitObjCMetadataUpdateFunction(IRGenModule &IGM,
 /// does not have statically-emitted metadata.
 bool irgen::hasObjCResilientClassStub(IRGenModule &IGM, ClassDecl *D) {
   assert(IGM.getClassMetadataStrategy(D) == ClassMetadataStrategy::Resilient);
-  return (!D->isGenericContext() &&
-          IGM.ObjCInterop &&
-          IGM.Context.LangOpts.EnableObjCResilientClassStubs);
+  return IGM.ObjCInterop && !D->isGenericContext();
 }
 
 void irgen::emitObjCResilientClassStub(IRGenModule &IGM, ClassDecl *D) {

lib/TBDGen/TBDGen.cpp

@@ -379,13 +379,16 @@ void TBDGenVisitor::visitClassDecl(ClassDecl *CD) {
 
   visitNominalTypeDecl(CD);
 
+  bool resilientAncestry = CD->checkAncestry(AncestryFlags::ResilientOther);
+
   // Types with resilient superclasses have some extra symbols.
-  if (CD->checkAncestry(AncestryFlags::ResilientOther) ||
-      CD->hasResilientMetadata()) {
+  if (resilientAncestry || CD->hasResilientMetadata()) {
     addSymbol(LinkEntity::forClassMetadataBaseOffset(CD));
+  }
 
-    auto &Ctx = CD->getASTContext();
-    if (Ctx.LangOpts.EnableObjCResilientClassStubs) {
+  auto &Ctx = CD->getASTContext();
+  if (Ctx.LangOpts.EnableObjCInterop) {
+    if (resilientAncestry) {
       addSymbol(LinkEntity::forObjCResilientClassStub(
           CD, TypeMetadataAddress::AddressPoint));
     }

test/Interpreter/objc_class_resilience_stubs.swift

@@ -3,7 +3,7 @@
 // RUN: %target-build-swift-dylib(%t/%target-library-name(resilient_struct)) -enable-library-evolution %S/../Inputs/resilient_struct.swift -emit-module -emit-module-path %t/resilient_struct.swiftmodule
 // RUN: %target-codesign %t/%target-library-name(resilient_struct)
 
-// RUN: %target-build-swift-dylib(%t/%target-library-name(resilient_objc_class)) -I %t -L %t -lresilient_struct -enable-library-evolution %S/../Inputs/resilient_objc_class.swift -emit-module -emit-module-path %t/resilient_objc_class.swiftmodule -Xfrontend -enable-resilient-objc-class-stubs
+// RUN: %target-build-swift-dylib(%t/%target-library-name(resilient_objc_class)) -I %t -L %t -lresilient_struct -enable-library-evolution %S/../Inputs/resilient_objc_class.swift -emit-module -emit-module-path %t/resilient_objc_class.swiftmodule
 // RUN: %target-codesign %t/%target-library-name(resilient_objc_class)
 
 // RUN: %target-build-swift %s -L %t -I %t -lresilient_struct -lresilient_objc_class -o %t/main %target-rpath(%t) -Xfrontend -enable-resilient-objc-class-stubs