Rollup merge of #86242 - BoxyUwU:rustdoc-const-evaluatable-ice, r=oli-obk

rustdoc- dont ICE on `ConstEvaluatable` predicates

Fixes #77647

rustdoc doesn't need to be handling these as you cant write them, they just get added implicitly when you write a where clause containing an expression.

src/test/rustdoc/const-generics/const-evaluatable-checked.rs

@@ -0,0 +1,7 @@
+#![crate_name = "foo"]
+#![feature(const_evaluatable_checked, const_generics)]
+#![allow(incomplete_features)]
+// make sure that `ConstEvaluatable` predicates dont cause rustdoc to ICE #77647
+// @has foo/struct.Ice.html '//pre[@class="rust struct"]' \
+//      'pub struct Ice<const N: usize> where [(); N + 1]: ;'
+pub struct Ice<const N: usize> where [(); N + 1]:;