[Bug tree-optimization/64715] [5.0 regression] __builtin_object_size (..., 1) fails to locate subobject

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64715

--- Comment #5 from Richard Biener <rguenth at gcc dot gnu.org> ---
Note that if I fix this the only possible fix will complain for

  char *p = (char *)&a;
  p += 4;
...

as well.