[Bug c/58540] Incorrect warning message for '*=' statement and different results based on optimization

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58540

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to bernardwidynski from comment #2)
> Bear with me if I protest further.
> 
> Logic requires that the "=" be executed before the "*="
> 
> I think that gcc should use this logic when compiling a program.

= and *= are not sequence points (in C90/C99/C++98 terms, C11 changes the terms
but the rule dealing with =/*= are the same).