[Bug fortran/101757] Simple integer assigment fails (off-seted by -1) when compiling with -O3

[federico.perini at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101757

--- Comment #2 from federico <federico.perini at gmail dot com> ---
Tested on godbolt.org: 

https://godbolt.org/z/sPsdE6Y3W

works on: 5.5, 6.3, all 10, all 11
error on: all 7, all 8, all 9