ASSERT FAILURE drwrap.c:1838: pt->wrap_level < 64 (max wrapped nesting reached)

When using GCC's support for nested functions and labels as values (nonlocal gotos), stack unwinding is getting missed, and can trigger this assertion in release mode, aborting the program. This issue is split from #3175; see [this repository](https://github.com/ddcc/stamp-tinySTM) for a testcase.