correctly track freed bytes in array_to_string (#54309)

Should fix #54275.

src/array.c

@@ -479,6 +479,7 @@ JL_DLLEXPORT jl_value_t *jl_array_to_string(jl_array_t *a)
             return o;
         }
     }
+    jl_gc_count_freed(jl_array_nbytes(a));
     a->nrows = 0;
     a->length = 0;
     a->maxsize = 0;

src/gc.c

@@ -1128,6 +1128,13 @@ void jl_gc_count_allocd(size_t sz) JL_NOTSAFEPOINT
         jl_atomic_load_relaxed(&ptls->gc_num.allocd) + sz);
 }
 
+void jl_gc_count_freed(size_t sz) JL_NOTSAFEPOINT
+{
+    jl_ptls_t ptls = jl_current_task->ptls;
+    jl_atomic_store_relaxed(&ptls->gc_num.freed,
+        jl_atomic_load_relaxed(&ptls->gc_num.freed) + sz);
+}
+
 static void combine_thread_gc_counts(jl_gc_num_t *dest) JL_NOTSAFEPOINT
 {
     int gc_n_threads;

src/gc.h

@@ -622,8 +622,6 @@ void gc_stats_big_obj(void);
 // For debugging
 void gc_count_pool(void);
 
-size_t jl_array_nbytes(jl_array_t *a) JL_NOTSAFEPOINT;
-
 JL_DLLEXPORT void jl_enable_gc_logging(int enable);
 JL_DLLEXPORT uint32_t jl_get_num_stack_mappings(void);
 void _report_gc_finished(uint64_t pause, uint64_t freed, int full, int recollect) JL_NOTSAFEPOINT;

src/julia_internal.h

@@ -569,7 +569,9 @@ JL_DLLEXPORT void JL_NORETURN jl_throw_out_of_memory_error(void);
 JL_DLLEXPORT int64_t jl_gc_diff_total_bytes(void) JL_NOTSAFEPOINT;
 JL_DLLEXPORT int64_t jl_gc_sync_total_bytes(int64_t offset) JL_NOTSAFEPOINT;
 void jl_gc_track_malloced_array(jl_ptls_t ptls, jl_array_t *a) JL_NOTSAFEPOINT;
+size_t jl_array_nbytes(jl_array_t *a) JL_NOTSAFEPOINT;
 void jl_gc_count_allocd(size_t sz) JL_NOTSAFEPOINT;
+void jl_gc_count_freed(size_t sz) JL_NOTSAFEPOINT;
 void jl_gc_run_all_finalizers(jl_task_t *ct);
 void jl_release_task_stack(jl_ptls_t ptls, jl_task_t *task);
 void jl_gc_add_finalizer_(jl_ptls_t ptls, void *v, void *f) JL_NOTSAFEPOINT;