Function Perl_sv_cat_decode 

pub unsafe fn Perl_sv_cat_decode(
    my_perl: *mut PerlInterpreter,
    dsv: *mut SV,
    encoding: *mut SV,
    ssv: *mut SV,
    offset: *mut c_int,
    tstr: *mut c_char,
    tlen: c_int,
) -> bool

thx shim for crate::Perl_sv_cat_decode.