[Bug c/67925] docs lie about being unable to inline function call before definition

[arkadiusz at drabczyk dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67925

--- Comment #1 from Arkadiusz Drabczyk <arkadiusz at drabczyk dot org> ---
BTW, the same incorrect wording is repeated in doc/extend.texi in GCC source
tarball.