Function CopLABEL_len_flags 

pub unsafe fn CopLABEL_len_flags(
    my_perl: *mut PerlInterpreter,
    c: *mut COP,
    len: *mut STRLEN,
    flags: *mut U32,
) -> *const c_char

thx shim for crate::CopLABEL_len_flags.