Why does GCC compiler optimize out variable foo entirely?

1. it can reason that it will never return from an infinite loop and thus there is no possibility of this variable being used in any other translation unit past this point
2. the variable is NOT volatile qualified meaning that accessing it will not change the observable behavior

Code:

int foo;

int main(void)
{
    foo = 10;

    while(1)
    {
        // Infinite loop never returns
    }
}

https://godbolt.org/z/5ebvbszE9