roc glue doesn't support 5 or more tags in a recursive union

[lukewilliamboswell]

Roc glue currently panics when you define 5 or more tags in a recursive union. This is due to the pointer tagging optimisation, and so glue will need to generate different code in this case.

luke@192-168-1-108 tui % roc glue platform/main.roc asdf.rs
thread 'main' panicked at 'not yet implemented: Support 5 tags in a recursive tag union on target_info TargetInfo { architecture: Aarch32, operating_system: Unix }. (This is too many tags for pointer tagging to work, so we need to generate different glue.)', crates/glue/src/rust_glue.rs:779:21
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

# TODO roc glue can't support more elements in this recusrive tage here yet
Elem : [
    Block BlockConfig,
    Paragraph ParagraphConfig,
    ListItems ListConfig,
    Layout (List Elem) LayoutConfig,
    SomeOtherWidget (List Elem), # Roc glue will work if we remove this Tag.
]