Make sure this testcase keeps crashing with -O3. Recent optimization improvements made LLVM realize the store-to-null was unavoidable, so it deleted all of main() and replaced it with 'unreachable'. Because the body of main() no longer even contained a return instruction, calling it caused random code to be ran instead. This happened to be the code that links in the ModuleInfo on my machine, which then returned "successfully".

module tangotests.sync2;

class Lock
{
}

const Lock lock;

static this()
{
    lock = new Lock;
}

void main()
{
    size_t id;
    synchronized(lock) id = 2;
}