Function exclude_pattern_compiles 

pub fn exclude_pattern_compiles(pattern: &str) -> bool

Whether every glob an exclude pattern turns into compiles.

An exclude pattern reaches two consumers: ExcludeMatchers compiles each expansion with globset, and the walker adds each as an ignore override. Both are mirrored here so a caller holding only the pattern can tell whether either would reject it, which is also when either would print it.