The patterns used by [ServeMux] allow multiple spaces matching

If the argument to [FileInfoHeader] implements the new [FileInfoNames]
interface, then the interface methods will be used to set the Uname/Gname
of the file header. This allows applications to override the system-dependent

field, [`Policies`](/pkg/crypto/x509/#Certificate.Policies), which supports
certificate policy OIDs with components larger than 31 bits. By default this
field is only used during parsing, when it is populated with policy OIDs, but
not used during marshaling. It can be used to marshal these larger OIDs, instead
of the existing PolicyIdentifiers field, by using the
[`x509usepolicies` setting.](/pkg/crypto/x509/#CreateCertificate).

Earlier versions of Go used channels with a one-element buffer,
making it difficult to use `Reset` and `Stop` correctly.
A visible effect of this change is that `len` and `cap` of timer channels
now returns 0 instead of 1, which may affect programs that
poll the length to decide whether a receive on the timer channel
will succeed.
Such code should use a non-blocking receive instead.

The `debug/elf` package now defines [PT_OPENBSD_NOBTCFI]. This [ProgType] is
used to disable Branch Tracking Control Flow Integrity (BTCFI) enforcement

Any value of comparable type may be canonicalized with the new
`Make[T]` function, which produces a reference to a canonical copy of
the value in the form of a `Handle[T]`.
Two `Handle[T]` are equal if and only if the values used to produce the
handles are equal, allowing programs to deduplicate values and reduce
their memory footprint.
Comparing two `Handle[T]` values is efficient, reducing down to a simple

pkg debug/elf, const DT_TLSDESC_GOT DynTag
pkg debug/elf, const DT_TLSDESC_PLT = 1879047926
pkg debug/elf, const DT_TLSDESC_PLT DynTag
pkg debug/elf, const DT_USED = 2147483646
pkg debug/elf, const DT_USED DynTag
pkg debug/elf, const DT_VALRNGHI = 1879047679
pkg debug/elf, const DT_VALRNGHI DynTag
pkg debug/elf, const DT_VALRNGLO = 1879047424
pkg debug/elf, const DT_VALRNGLO DynTag

Unlike many projects on GitHub, the Go project does not use its bug tracker for general discussion or asking questions.
We only use our bug tracker for tracking bugs and tracking proposals going through the [Proposal Process](https://go.dev/s/proposal-process).

For asking questions, see:

* [The golang-nuts mailing list](https://groups.google.com/d/forum/golang-nuts)

* [The Go Forum](https://forum.golangbridge.org/), a web-based forum

### Iterators

The new [`iter` package](/pkg/iter/) provides the basic definitions for

set to 'on' or 'auto', and if you use a go.work file, set GOWORK=off.

Requirements may be added, updated, and removed with 'go get'.
The vendor directory may be updated with 'go mod vendor'.
A typical sequence might be:

    cd src  # or src/cmd
    go get golang.org/x/net@master
    go mod tidy
    go mod vendor

Use caution when passing '-u' to 'go get'. The '-u' flag updates