Only call new_block once.

Author: cjgillot

compiler/rustc_mir_transform/src/add_call_guards.rs

@@ -101,22 +101,22 @@ impl<'tcx> crate::MirPass<'tcx> for AddCallGuards {
             let is_cleanup = block.is_cleanup;
             let term = block.terminator_mut();
             let source_info = term.source_info;
-            match action {
+            let destination = match action {
                 Action::Call => {
                     let TerminatorKind::Call { target: Some(ref mut destination), .. } = term.kind
                     else {
                         unreachable!()
                     };
-                    *destination = new_block(source_info, is_cleanup, *destination);
+                    destination
                 }
                 Action::Asm { target_index } => {
                     let TerminatorKind::InlineAsm { ref mut targets, .. } = term.kind else {
                         unreachable!()
                     };
-                    targets[target_index] =
-                        new_block(source_info, is_cleanup, targets[target_index]);
+                    &mut targets[target_index]
                 }
-            }
+            };
+            *destination = new_block(source_info, is_cleanup, *destination);
         }
 
         debug!("Broke {} N edges", new_blocks.len());