Rollup merge of #94091 - GuillaumeGomez:rustdoc-const-computed-value, r=oli-obk

Fix rustdoc const computed value

Fixes #85088.

It looks like this now (instead of hexadecimal):

![Screenshot from 2022-02-17 17-55-39](https://user-images.githubusercontent.com/3050060/154532115-0f9861a0-406f-4c9c-957f-32bedd8aca7d.png)

r? ````@oli-obk````

src/librustdoc/clean/utils.rs

@@ -302,7 +302,11 @@ fn print_const_with_custom_print_scalar(tcx: TyCtxt<'_>, ct: ty::Const<'_>) -> S
     // For all other types, fallback to the original `pretty_print_const`.
     match (ct.val(), ct.ty().kind()) {
         (ty::ConstKind::Value(ConstValue::Scalar(int)), ty::Uint(ui)) => {
-            format!("{}{}", format_integer_with_underscore_sep(&int.to_string()), ui.name_str())
+            format!(
+                "{}{}",
+                format_integer_with_underscore_sep(&int.rustdoc_display()),
+                ui.name_str()
+            )
         }
         (ty::ConstKind::Value(ConstValue::Scalar(int)), ty::Int(i)) => {
             let ty = tcx.lift(ct.ty()).unwrap();