Inconsistent builder accessibility

[bboyle1234]

With the following declaration:

    [ImmutableClass(Options = ImmutableClassOptions.IncludeOperatorEquals | ImmutableClassOptions.ExcludeToString | ImmutableClassOptions.ExcludeWith, ConstructorAccessLevel = ConstructorAccessLevel.Internal, BuilderAccessLevel = BuilderAccessLevel.Internal)]
    public sealed partial class IndicativeIndexRollover {

We get the following issue. The ToBuilder method accessibility needs to match the builder class accessibility.