fix: only ref match non-unknown value items

[A4-Tacks]

Fixes #22324

Example

struct S<T>(T);
impl<T> core::ops::Deref for S<T> {
    type Target = T;
}
fn foo<T>(s: &u32) {}
fn main() {
    let ssss = S();
    foo($0);
}

Before this PR

lc ssss S<{unknown}> [local]
lc &ssss [type+local]
st S S<{unknown}> []
st &S [type]
...

After this PR

lc ssss S<{unknown}> [local]
st S S<{unknown}> []
...