Update `indexmap` and use `IndexMap::append`

1 files changed, 2 insertions, 2 deletions

diff --git a/compiler/rustc_monomorphize/src/partitioning.rs b/compiler/rustc_monomorphize/src/partitioning.rs
index 65a3d8d1742..92902185e8b 100644
--- a/compiler/rustc_monomorphize/src/partitioning.rs
+++ b/compiler/rustc_monomorphize/src/partitioning.rs
@@ -371,7 +371,7 @@ fn merge_codegen_units<'tcx>(
         // Move the items from `cgu_src` to `cgu_dst`. Some of them may be
         // duplicate inlined items, in which case the destination CGU is
         // unaffected. Recalculate size estimates afterwards.
-        cgu_dst.items_mut().extend(cgu_src.items_mut().drain(..));
+        cgu_dst.items_mut().append(cgu_src.items_mut());
         cgu_dst.compute_size_estimate();
 
         // Record that `cgu_dst` now contains all the stuff that was in
@@ -410,7 +410,7 @@ fn merge_codegen_units<'tcx>(
         // Move the items from `smallest` to `second_smallest`. Some of them
         // may be duplicate inlined items, in which case the destination CGU is
         // unaffected. Recalculate size estimates afterwards.
-        second_smallest.items_mut().extend(smallest.items_mut().drain(..));
+        second_smallest.items_mut().append(smallest.items_mut());
         second_smallest.compute_size_estimate();
 
         // Don't update `cgu_contents`, that's only for incremental builds.