[Bug middle-end/123115] -Wunused-but-set-variable warning for EH_RETURN_DATA_REGNO on nvptx

[sjames at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123115

--- Comment #1 from Sam James <sjames at gcc dot gnu.org> ---
See r6-156-g9a52250502b8e0 and r15-9470-gfe283dba774be5.