fn void test1()
{
    int x;
    if (x == 0) return;
    return test1();
}
/* #expect: returning_void.ll

  %x = alloca i32, align 4
  store i32 0, ptr %x, align 4
  %0 = load i32, ptr %x, align 4
  %eq = icmp eq i32 %0, 0
  br i1 %eq, label %if.then, label %if.exit

if.then:
  ret void

if.exit:
  call void @returning_void.test1()
  ret void
