[Bug tree-optimization/126009] memset erroneously indicating "region of size 0" instead of reporting possibly-null pointer

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126009

--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> ---
The wording of the diagnostic is still misleading (but ISTR I added a note:
indicating there might be a NULL pointer).