move singleton pages to the full queue at allocation time

src/page.c

@@ -990,14 +990,21 @@ void* _mi_malloc_generic(mi_heap_t* heap, size_t size, bool zero, size_t huge_al
   mi_assert_internal(mi_page_block_size(page) >= size);
 
   // and try again, this time succeeding! (i.e. this should never recurse through _mi_page_malloc)
+  void* p;
   if mi_unlikely(zero && mi_page_is_huge(page)) {
     // note: we cannot call _mi_page_malloc with zeroing for huge blocks; we zero it afterwards in that case.
-    void* p = _mi_page_malloc(heap, page, size);
+    p = _mi_page_malloc(heap, page, size);
     mi_assert_internal(p != NULL);
     _mi_memzero_aligned(p, mi_page_usable_block_size(page));
-    return p;
   }
   else {
-    return _mi_page_malloc_zero(heap, page, size, zero);
+    p = _mi_page_malloc_zero(heap, page, size, zero);
+    mi_assert_internal(p != NULL);
   }
+  // move singleton pages to the full queue
+  if (page->reserved == page->used) {
+    mi_assert_internal(page->reserved == 1);
+    mi_page_to_full(page, mi_page_queue_of(page));
+  }
+  return p;
 }