Make sure to count reused cgus towards the count of jobs done

src/concurrency_limiter.rs

@@ -49,6 +49,11 @@ impl ConcurrencyLimiter {
             state = self.available_token_condvar.wait(state).unwrap();
         }
     }
+
+    pub(super) fn job_already_done(&mut self) {
+        let mut state = self.state.lock().unwrap();
+        state.job_already_done();
+    }
 }
 
 impl Drop for ConcurrencyLimiter {
@@ -137,6 +142,14 @@ mod state {
             self.assert_invariants();
         }
 
+        pub(super) fn job_already_done(&mut self) {
+            self.assert_invariants();
+            self.pending_jobs -= 1;
+            self.assert_invariants();
+            self.drop_excess_capacity();
+            self.assert_invariants();
+        }
+
         fn drop_excess_capacity(&mut self) {
             self.assert_invariants();
             if self.active_jobs == self.pending_jobs {

src/driver/aot.rs

@@ -391,6 +391,7 @@ pub(crate) fn run_aot(
                     }
                     CguReuse::PreLto => unreachable!(),
                     CguReuse::PostLto => {
+                        concurrency_limiter.job_already_done();
                         OngoingModuleCodegen::Sync(reuse_workproduct_for_cgu(tcx, &*cgu))
                     }
                 }