poll the length to decide whether a receive on the timer channel
will succeed.
Such code should use a non-blocking receive instead.

These new behaviors are only enabled when the main Go program
is in a module with a `go.mod` `go` line using Go 1.23.0 or later.
When Go 1.23 builds older programs, the old behaviors remain in effect.
The new [GODEBUG setting](/doc/godebug) [`asynctimerchan=1`](/pkg/time/#NewTimer)

The files should be in the subdirectory for the package with the new
API, and should be named after the issue number of the API proposal.
For example, if the directory `6-stdlib/99-minor` is present,
then an `api/next` file with the line

    pkg net/http, function F #12345

should have a corresponding file named `doc/next/6-stdlib/99-minor/net/http/12345.md`.
At a minimum, that file should contain either a full sentence or a TODO,

pkg syscall (darwin-386), const IPPROTO_DDP = 37
pkg syscall (darwin-386), const IPPROTO_DGP = 86
pkg syscall (darwin-386), const IPPROTO_DIVERT = 254
pkg syscall (darwin-386), const IPPROTO_DONE = 257
pkg syscall (darwin-386), const IPPROTO_DSTOPTS = 60
pkg syscall (darwin-386), const IPPROTO_EGP = 8
pkg syscall (darwin-386), const IPPROTO_EMCON = 14
pkg syscall (darwin-386), const IPPROTO_ENCAP = 98

pkg context, func WithValue(Context, interface{}, interface{}) Context
pkg context, type CancelFunc func()
pkg context, type Context interface { Deadline, Done, Err, Value }
pkg context, type Context interface, Deadline() (time.Time, bool)
pkg context, type Context interface, Done() <-chan struct
pkg context, type Context interface, Err() error
pkg context, type Context interface, Value(interface{}) interface{}
pkg context, var Canceled error

pkg log/slog, type Source struct #59280
pkg log/slog, type Source struct, File string #59280
pkg log/slog, type Source struct, Function string #59280
pkg log/slog, type Source struct, Line int #59280
pkg log/slog, type TextHandler struct #56345
pkg log/slog, type Value struct #56345
pkg maps, func Clone[$0 interface{ ~map[$1]$2 }, $1 comparable, $2 interface{}]($0) $0 #57436

pkg syscall (freebsd-386-cgo), const IPPROTO_DDP ideal-int
pkg syscall (freebsd-386-cgo), const IPPROTO_DGP ideal-int
pkg syscall (freebsd-386-cgo), const IPPROTO_DIVERT ideal-int
pkg syscall (freebsd-386-cgo), const IPPROTO_DONE ideal-int
pkg syscall (freebsd-386-cgo), const IPPROTO_DSTOPTS ideal-int
pkg syscall (freebsd-386-cgo), const IPPROTO_EGP ideal-int
pkg syscall (freebsd-386-cgo), const IPPROTO_EMCON ideal-int