[Serialization] Accept DeclDeserializationUnsafe where we accepted XRef failures

Author: xymus

lib/Serialization/Deserialization.cpp

@@ -7088,7 +7088,8 @@ static llvm::Error consumeErrorIfXRefNonLoadedModule(llvm::Error &&error) {
     // Missing module errors are most likely caused by an
     // implementation-only import hiding types and decls.
     // rdar://problem/60291019
-    if (error.isA<XRefNonLoadedModuleError>()) {
+    if (error.isA<XRefNonLoadedModuleError>() ||
+        error.isA<UnsafeDeserializationError>()) {
       consumeError(std::move(error));
       return llvm::Error::success();
     }
@@ -7100,7 +7101,8 @@ static llvm::Error consumeErrorIfXRefNonLoadedModule(llvm::Error &&error) {
       auto errorInfo = takeErrorInfo(std::move(error));
       auto *TE = static_cast<TypeError*>(errorInfo.get());
 
-      if (TE->underlyingReasonIsA<XRefNonLoadedModuleError>()) {
+      if (TE->underlyingReasonIsA<XRefNonLoadedModuleError>() ||
+          TE->underlyingReasonIsA<UnsafeDeserializationError>()) {
         consumeError(std::move(errorInfo));
         return llvm::Error::success();
       }
@@ -7436,6 +7438,7 @@ void ModuleFile::finishNormalConformance(NormalProtocolConformance *conformance,
       // errors - we're just doing a best effort to create the
       // module in that case.
       if (witnessSubstitutions.errorIsA<XRefNonLoadedModuleError>() ||
+          witnessSubstitutions.errorIsA<UnsafeDeserializationError>() ||
           allowCompilerErrors()) {
         consumeError(witnessSubstitutions.takeError());
         isOpaque = true;