Have a single struct for queries and hook

compiler/rustc_middle/src/util/mod.rs

@@ -5,3 +5,26 @@ pub mod find_self_call;
 
 pub use call_kind::{call_kind, CallDesugaringKind, CallKind};
 pub use find_self_call::find_self_call;
+
+#[derive(Default, Copy, Clone)]
+pub struct Providers {
+    pub queries: rustc_middle::query::Providers,
+    pub hooks: rustc_middle::hooks::Providers,
+}
+
+/// Backwards compatibility hack to keep the diff small. This
+/// gives direct access to the `queries` field's fields, which
+/// are what almost everything wants access to.
+impl std::ops::DerefMut for Providers {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.queries
+    }
+}
+
+impl std::ops::Deref for Providers {
+    type Target = rustc_middle::query::Providers;
+
+    fn deref(&self) -> &Self::Target {
+        &self.queries
+    }
+}