[Bug tree-optimization/101832] __builtin_object_size(P->M, 1) where M ends with a flex-array behaves like sizeof()

[qinzhao at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101832

--- Comment #14 from qinzhao at gcc dot gnu.org ---
since it's opened again GCC12, the patch need to be backported to GCC12. then
will be closed at that time.