Update py/gc.c

Co-authored-by: Dan Halbert <[email protected]>

Author: tannewt

py/gc.c

@@ -331,6 +331,7 @@ static size_t compute_heap_size(size_t total_blocks) {
 static bool gc_try_add_heap(size_t failed_alloc) {
     // 'needed' is the size of a heap large enough to hold failed_alloc, with
     // the additional metadata overheads as calculated in gc_setup_area().
+    // CIRCUITPY-CHANGE: calculation of how much to grow the heap
     size_t total_new_blocks = (failed_alloc + BYTES_PER_BLOCK - 1) / BYTES_PER_BLOCK;
     size_t needed = compute_heap_size(total_new_blocks);