* `zig test` gainst `--test-evented-io` parameter and gains the ability
to seamlessly run async tests.
* `std.ChildProcess` opens its child process pipe with O_NONBLOCK when
using evented I/O
* `std.io.getStdErr()` gives a File that is blocking even in evented
I/O mode.
* Delete `std.event.fs`. The functionality is now merged into `std.fs`
and async file system access (using a dedicated thread) is
automatically handled.
* `std.fs.File` can be configured to specify whether its handle is
expected to block, and whether that is OK to block even when in
async I/O mode. This makes async I/O work correctly for e.g. the
file system as well as network.
* `std.fs.File` has some deprecated functions removed.
* Missing readv,writev,pread,pwrite,preadv,pwritev functions are added
to `std.os` and `std.fs.File`. They are all integrated with async
I/O.
* `std.fs.Watch` is still bit rotted and needs to be audited in light
of the new async/await syntax.
* `std.io.OutStream` integrates with async I/O
* linked list nodes in the std lib have default `null` values for
`prev` and `next`.
* Windows async I/O integration is enabled for reading/writing file
handles.
* Added `std.os.mode_t`. Integer sizes need to be audited.
* Fixed#4403 which was causing compiler to crash.
This is working towards:
./zig test ../test/stage1/behavior.zig --test-evented-io
Which does not successfully build yet. I'd like to enable behavioral
tests and std lib tests with --test-evented-io in the test matrix in the
future, to prevent regressions.