[Bug c/87588] gcc does not warn about unused variable which references to itself

[dmalcolm at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87588

--- Comment #2 from David Malcolm <dmalcolm at gcc dot gnu.org> ---
FWIW here's the reproducer in Compiler Explorer:
https://godbolt.org/z/54KzMcasP