Add `GC.auto_compact= true/false` and `GC.auto_compact`

* `GC.auto_compact=`, `GC.auto_compact` can be used to control when
  compaction runs.  Setting `auto_compact=` to true will cause
  compaction to occurr duing major collections.  At the moment,
  compaction adds significant overhead to major collections, so please
  test first!

[Feature #17176]

1 files changed, 3 insertions, 0 deletions

diff --git a/compile.c b/compile.c
index bf2c4f88a6..f6f5a1d848 100644
--- a/compile.c
+++ b/compile.c
@@ -1304,6 +1304,9 @@ new_insn_send(rb_iseq_t *iseq, int line_no, ID id, VALUE argc, const rb_iseq_t *
     VALUE *operands = compile_data_calloc2(iseq, sizeof(VALUE), 2);
     operands[0] = (VALUE)new_callinfo(iseq, id, FIX2INT(argc), FIX2INT(flag), keywords, blockiseq != NULL);
     operands[1] = (VALUE)blockiseq;
+    if (blockiseq) {
+        RB_OBJ_WRITTEN(iseq, Qundef, blockiseq);
+    }
     return new_insn_core(iseq, line_no, BIN(send), 2, operands);
 }