[Bug c/91225] Warning should be produced for a variable initialized by itself at the declaration

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91225

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This is/was documented as a way to get rid of uninitialized warnings. So if
this changes, please change the documentation too.  Also -Wself-init should
cause the initialized warnings to come back.  Note I implemented that option
which is why I know some of the history around it.

Note also there is another bug requesting the option be enabled by default too.