Remove some _cursor/_results suffixes.

Results and cursors normally don't have suffixes. By slightly changing
the order here and introducing one shadowed local variable, we can deal
with results first, then convert to cursors, removing the need for the
suffixes.

Author: nnethercote

compiler/rustc_mir_transform/src/coroutine.rs

@@ -672,18 +672,17 @@ fn locals_live_across_suspend_points<'tcx>(
 
     // Calculate the MIR locals which have been previously
     // borrowed (even if they are still active).
-    let borrowed_locals_results =
+    let borrowed_locals =
         MaybeBorrowedLocals.into_engine(tcx, body).pass_name("coroutine").iterate_to_fixpoint();
 
-    let mut borrowed_locals_cursor = borrowed_locals_results.clone().into_results_cursor(body);
-
-    // Calculate the MIR locals that we actually need to keep storage around
-    // for.
-    let mut requires_storage_cursor = MaybeRequiresStorage::new(body, borrowed_locals_results)
+    // Calculate the MIR locals for which we need to keep storage around.
+    let mut requires_storage = MaybeRequiresStorage::new(body, borrowed_locals.clone())
         .into_engine(tcx, body)
         .iterate_to_fixpoint()
         .into_results_cursor(body);
 
+    let mut borrowed_locals = borrowed_locals.into_results_cursor(body);
+
     // Calculate the liveness of MIR locals ignoring borrows.
     let mut liveness = MaybeLiveLocals
         .into_engine(tcx, body)
@@ -715,8 +714,8 @@ fn locals_live_across_suspend_points<'tcx>(
                 // If a borrow is converted to a raw reference, we must also assume that it lives
                 // forever. Note that the final liveness is still bounded by the storage liveness
                 // of the local, which happens using the `intersect` operation below.
-                borrowed_locals_cursor.seek_before_primary_effect(loc);
-                live_locals.union(borrowed_locals_cursor.get());
+                borrowed_locals.seek_before_primary_effect(loc);
+                live_locals.union(borrowed_locals.get());
             }
 
             // Store the storage liveness for later use so we can restore the state
@@ -727,8 +726,8 @@ fn locals_live_across_suspend_points<'tcx>(
             // Locals live are live at this point only if they are used across
             // suspension points (the `liveness` variable)
             // and their storage is required (the `storage_required` variable)
-            requires_storage_cursor.seek_before_primary_effect(loc);
-            live_locals.intersect(requires_storage_cursor.get());
+            requires_storage.seek_before_primary_effect(loc);
+            live_locals.intersect(requires_storage.get());
 
             // The coroutine argument is ignored.
             live_locals.remove(SELF_ARG);
@@ -758,7 +757,7 @@ fn locals_live_across_suspend_points<'tcx>(
         body,
         &saved_locals,
         always_live_locals.clone(),
-        requires_storage_cursor.into_results(),
+        requires_storage.into_results(),
     );
 
     LivenessInfo {