[Bug analyzer/123981] -Wanalyzer-null-dereference does not consider __seg_gs

[auto at fedang dot net]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123981

--- Comment #6 from Federico <auto at fedang dot net> ---
Hello Andrew and David, thanks for your quick response.
I tried my hand at making a patch and adding a testcase,
hopefully this will be of use to you.
I'm also sending this also to gcc-patches list.

PS: This is my first time contributing, hopefully I didn't do anything silly.