Replace type_alias_impl_trait by min_type_alias_impl_trait with no actual changes in behaviour

This makes `type_alias_impl_trait` not actually do anything anymore

src/test/rustdoc-ui/error-in-impl-trait/trait-alias.rs

@@ -1,5 +1,5 @@
 // check-pass
-#![feature(type_alias_impl_trait)]
+#![feature(min_type_alias_impl_trait)]
 
 pub trait ValidTrait {}
 type ImplTrait = impl ValidTrait;