Fix complex transi compact

[casperisfine]

I think this PR fixes the compaction issue, but now I run into the bug I was looking to in the first place:

$ make test/ruby/test_shapes.rb

TestShapes#test_evacuate_class_ivar_and_compaction [/Users/byroot/src/github.com/Shopify/ruby/test/ruby/test_shapes.rb:279]:
pid 83296 killed by SIGABRT (signal 6)
| <OBJ_INFO:gc_mark_ptr@gc.c:6966> 0x0000000107ccfc10 [0 M    ] T_NONE 
| /Users/byroot/src/github.com/Shopify/ruby/tool/lib/core_assertions.rb:524: [BUG] try to mark T_NONE object
| -- C level backtrace information -------------------------------------------
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(rb_vm_bugreport+0xb60) [0x1052bb5f0] vm_dump.c:1143
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(rb_vm_bugreport) (null):0
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(rb_bug_without_die+0xf0) [0x1050daa84] error.c:1042
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(rb_bug+0x1c) [0x1053b495c] error.c:1050
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(rb_gc_mark_weak+0x0) [0x1050fbce4] gc.c:6967
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(gc_mark_ptr) (null):0
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(gc_mark+0x10) [0x105100ad8] gc.c:7003
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(mark_method_entry) gc.c:6635
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(gc_mark_imemo) gc.c:7153
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(gc_mark_children) gc.c:7275
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(gc_mark_stacked_objects+0x78) [0x105108bd8] gc.c:7471
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(gc_mark_stacked_objects_incremental) gc.c:7503
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(gc_marks_rest+0xac) [0x1051089e0] gc.c:8693
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(gc_rest+0x110) [0x1050fa154] gc.c:9528
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(garbage_collect+0x5c) [0x1050fdf74] gc.c:9382
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(objspace_xmalloc0+0x70) [0x10510167c] gc.c:12408
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(vm_ccs_push+0x14c) [0x1052a2cfc] ./vm_insnhelper.c:1997
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(imemo_type_p+0x0) [0x105285d30] ./vm_insnhelper.c:2138
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(vm_cc_cme) ./vm_callinfo.h:394
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(vm_search_cc) ./vm_insnhelper.c:2140
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(rb_vm_search_method_slowpath) ./vm_insnhelper.c:2156
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(vm_search_method_slowpath0+0x24) [0x1052af124] ./vm_insnhelper.c:2177
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(vm_search_method_fastpath+0x10) [0x105287a4c] ./vm_insnhelper.c:2238
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(vm_sendish) ./vm_insnhelper.c:5581
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(vm_exec_core+0x31bc) [0x10528c344] insns.def:822
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(rb_vm_exec+0x1f4) [0x105287e90] vm.c:2467
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(rb_ec_exec_node+0xac) [0x1050e6ab4] eval.c:287
| /Users/byroot/src/github.com/Shopify/ruby/libruby.3.3.dylib(ruby_run_node+0x70) [0x1050e6998] eval.c:328
| /Users/byroot/src/github.com/Shopify/ruby/ruby(rb_main+0x1c) [0x1048bff18] ./main.c:39

[casperisfine]

It's crashing on:

          case VM_METHOD_TYPE_ISEQ:
            if (def->body.iseq.iseqptr) gc_mark(objspace, (VALUE)def->body.iseq.iseqptr);