rustc: Move stability functionality into queries

This commit primarily removes the `stability` field from `TyCtxt` as well as its
internal mutable state, instead using a query to build the stability index as
well as primarily using queries for other related lookups.

Like previous commits the calculation of the stability index is wrapped in a
`with_ignore` node to avoid regressing the current tests, and otherwise this
commit also introduces #44232 but somewhat intentionally so.

src/test/compile-fail/feature-gate/issue-43106-gating-of-builtin-attrs.rs

@@ -99,7 +99,8 @@
 
 // For #![crate_id], see issue #43142. (I cannot bear to enshrine current behavior in a test)
 
-#![feature                    ( x0600)] //~ WARN unused or unknown feature
+// FIXME(#44232) we should warn that this isn't used.
+#![feature                    ( x0600)]
 
 // For #![no_start], see issue #43144. (I cannot bear to enshrine current behavior in a test)
 

src/test/compile-fail/lint-output-format-2.rs

@@ -8,21 +8,21 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-// compile-flags: -F unused_features
 // aux-build:lint_output_format.rs
 
+// FIXME(#44232) we should warn that this isn't used.
 #![feature(foo)]
-//~^ ERROR unused or unknown feature
-//~| NOTE requested on the command line with `-F unused-features`
 
 #![feature(test_feature)]
+#![feature(rustc_attrs)]
 
 extern crate lint_output_format;
 use lint_output_format::{foo, bar};
 //~^ WARNING use of deprecated item: text
 //~| NOTE #[warn(deprecated)] on by default
 
-fn main() {
+#[rustc_error]
+fn main() { //~ ERROR: compilation successful
     let _x = foo();
     //~^ WARNING use of deprecated item: text
     //~| NOTE #[warn(deprecated)] on by default

src/test/compile-fail/lint-unknown-feature-default.rs

@@ -10,8 +10,10 @@
 
 // Tests the default for the unused_features lint
 
-#![deny(warnings)]
+// FIXME(#44232) we should warn that this isn't used.
+#![feature(this_is_not_a_feature)]
 
-#![feature(this_is_not_a_feature)] //~ ERROR: unused or unknown feature
+#![feature(rustc_attrs)]
 
-fn main() { }
+#[rustc_error]
+fn main() { } //~ ERROR: compilation successful

src/test/compile-fail/lint-unknown-feature.rs

@@ -8,8 +8,12 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![deny(unused_features)]
+#![warn(unused_features)]
 
-#![feature(this_is_not_a_feature)] //~ ERROR: unused or unknown feature
+// FIXME(#44232) we should warn that this isn't used.
+#![feature(this_is_not_a_feature)]
 
-fn main() {}
+#![feature(rustc_attrs)]
+
+#[rustc_error]
+fn main() {} //~ ERROR: compilation successful

src/test/compile-fail/stable-features.rs

@@ -12,8 +12,11 @@
 // language and lib features.
 
 #![deny(stable_features)]
+
 #![feature(test_accepted_feature)] //~ ERROR this feature has been stable since 1.0.0
-#![feature(rust1)] //~ ERROR this feature has been stable since 1.0.0
+
+// FIXME(#44232) we should error that this isn't used.
+#![feature(rust1)]
 
 fn main() {
     let _foo: Vec<()> = Vec::new();