[embedded] Actually, use 'nounwind' even with C++ interop on, add comment

Author: kubamracek

lib/IRGen/IRGenModule.cpp

@@ -1445,8 +1445,9 @@ void IRGenModule::constructInitialFnAttributes(
     Attrs.addAttribute("stack-protector-buffer-size", llvm::utostr(8));
   }
 
-  if (Context.LangOpts.hasFeature(Feature::Embedded) &&
-      !Context.LangOpts.EnableCXXInterop) {
+  // Mark as 'nounwind' to avoid referencing exception personality symbols, this
+  // is okay even with C++ interop on because the landinpads are trapping.
+  if (Context.LangOpts.hasFeature(Feature::Embedded)) {
     Attrs.addAttribute(llvm::Attribute::NoUnwind);
   }
 }

lib/IRGen/IRGenSIL.cpp

@@ -1846,8 +1846,9 @@ IRGenSILFunction::IRGenSILFunction(IRGenModule &IGM, SILFunction *f)
     CurFn->addFnAttr(llvm::Attribute::NoInline);
   }
 
-  if (IGM.Context.LangOpts.hasFeature(Feature::Embedded) &&
-      !IGM.Context.LangOpts.EnableCXXInterop) {
+  // Mark as 'nounwind' to avoid referencing exception personality symbols, this
+  // is okay even with C++ interop on because the landinpads are trapping.
+  if (IGM.Context.LangOpts.hasFeature(Feature::Embedded)) {
     CurFn->addFnAttr(llvm::Attribute::NoUnwind);
   }