Ignore nullabilities when comparing parameter types when generating exceptions

src/Features/Core/Portable/GenerateType/AbstractGenerateTypeService.GenerateNamedType.cs

@@ -130,7 +130,7 @@ private void AddMembers(ArrayBuilder<ISymbol> members, GenerateTypeOptionsResult
                 // caller.
                 if (_state.IsException &&
                     _state.BaseTypeOrInterfaceOpt.InstanceConstructors.Any(
-                        c => c.Parameters.Select(p => p.Type).SequenceEqual(parameterTypes)))
+                        c => c.Parameters.Select(p => p.Type).SequenceEqual(parameterTypes, AllNullabilityIgnoringSymbolComparer.Instance)))
                 {
                     return;
                 }