[Bug c/70749] error: storage size of ‘a’ isn’t known goes away with -Os

[ktkachov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70749

--- Comment #2 from ktkachov at gcc dot gnu.org ---
Trunk errors with or without optimisation.
GCC 5 and earlier don't error with optimisation.

If this behaviour is expected (and the bug is in the kernel sources) feel free
to close the report. I just thought it curious that the error depends on
optimisation level.