"defer" would allow programmers to specify cleanup code that is run when the scope is left for any reason, see https://thephd.dev/c2y-the-defer-technical-specification-its-time-go-go-go. A similar feature for the same purpose would also count, for example gcc's "cleanup" attribute or something like try/finally.
Resolves to whether this is included in the next (sixth) edition of ISO/IEC 9899. The close date will be extended if necessary, but it can be resolved as soon as the committee has finished the standard, even if the official publication takes longer.
There is now an open PR to implement it in clang: https://github.com/llvm/llvm-project/pull/162848
Also a patch for gcc: https://inbox.sourceware.org/gcc-patches/20251027231813.954-1-navi@vlhl.dev/T/
Having working implementations in these compilers will probably make it more likely to be added to the language.