Function Perl_refcounted_he_fetch_sv 

pub unsafe fn Perl_refcounted_he_fetch_sv(
    my_perl: *mut PerlInterpreter,
    chain: *const refcounted_he,
    key: *mut SV,
    hash: U32,
    flags: U32,
) -> *mut SV

thx shim for crate::Perl_refcounted_he_fetch_sv.