Parsing apparently enters infinite loop

[lukaslueg]

Using syn 2.0.77, the following reduced examples seems to never return (at least not before I kill it after several minutes). Notice that 2.0.61 returns, while 2.0.62 .. does not.

fn main() {
    syn::parse_str::<syn::File>("#[a=a=a<a<]");
}

fn main() {
    syn::parse_str::<syn::GenericParam>("a=<a<{a=a<a<}");
}

[lukaslueg]

Using 09d020f, #[r=6=r..1..] seems to run into the same problem.