fix OpenDirOptions.iterate=true to prevent panic in fs.cwd().openDir().iterate()

[snubydev]

Problem

Zig standard library has an issue [Closed] #12007 ziglang/zig#12007,
which requeres to set OpenDirOptions.iterate=true for std.fs.openDirAbsolute() etc, if we want to iterate the opened directory.

Reproduce

zig version: 0.12.0-dev.2750+5f9255829

zig build test

Result

.........thread 386773 panic: reached unreachable code
/opt/zig/lib/std/os.zig:5062:18: 0x116bcb1 in lseek_SET (test)
        .BADF => unreachable, // always a race condition
                 ^
/opt/zig/lib/std/fs/Dir.zig:343:40: 0x115fc04 in nextLinux (test)
                        posix.lseek_SET(self.dir.fd, 0) catch unreachable; // EBADF here likely means that the Dir was not opened with iteration permissions
                                       ^
/opt/zig/lib/std/fs/Dir.zig:327:34: 0x10eee97 in next (test)
            return self.nextLinux() catch |err| switch (err) {
                                 ^
/home/dad/projects/open-source/forks/zul/src/fs.zig:163:22: 0x10eedf8 in next (test)
  return self.it.next();
                     ^
/home/dad/projects/open-source/forks/zul/src/fs.zig:310:22: 0x10ef340 in test.fs.readDir: iterate (test)
   while (try it.next()) |entry| {
                     ^
/home/dad/projects/open-source/forks/zul/test_runner.zig:43:24: 0x10a6a75 in main (test)
  const result = t.func();
                       ^
/opt/zig/lib/std/start.zig:511:37: 0x10a178a in posixCallMainAndExit (test)
            const result = root.main() catch |err| {
                                    ^
/opt/zig/lib/std/start.zig:253:5: 0x10a12e1 in _start (test)
    asm volatile (switch (native_arch) {
    ^
???:?:?: 0x0 in ??? (???)
test
└─ run test failure
error: the following command terminated unexpectedly:
/home/dad/projects/open-source/forks/zul/zig-cache/o/877809e6c15178f21cfd5acb1470a64f/test
Build Summary: 1/3 steps succeeded; 1 failed (disable with --summary none)
test transitive failure
└─ run test failure
error: the following build command failed with exit code 1:
/home/dad/projects/open-source/forks/zul/zig-cache/o/169cde244f218bf0344175253995abab/build /opt/zig/zig /home/dad/projects/open-source/forks/zul /home/dad/projects/open-source/forks/zul/zig-cache /home/dad/.cache/zig --seed 0x247a7b35 -Zcb1f239bde67e419 test

Solution

Add iterate option when we open a Dir and iterate later .{iterate = true}

[karlseguin]

thanks