The patterns used by [ServeMux] allow multiple spaces matching

This setting will be removed in a future release, Go 1.22 at the earliest.

### Go 1.10

Go 1.10 changed how build caching worked and added test caching, along
with the [`gocacheverify`, `gocachehash`, and `gocachetest` settings](/cmd/go/#hdr-Build_and_test_caching).
There is no plan to remove these settings.

### Go 1.6

Go 1.6 introduced transparent support for HTTP/2,

the CL (or ask the author to do so).

At the end of the development cycle, the files will be merged by being
concatenated in sorted order by pathname. Files in the directory matching the
glob "*stdlib/*minor" are treated specially. They should be in subdirectories
corresponding to standard library package paths, and headings for those package
paths will be generated automatically.

pkg syscall (darwin-amd64-cgo), const ImplementsGetwd = false
pkg syscall (darwin-amd64-cgo), func Fchflags(string, int) error
pkg syscall (freebsd-386), const AF_MAX = 38
pkg syscall (freebsd-386), const DLT_MATCHING_MAX = 242
pkg syscall (freebsd-386), const ELAST = 94
pkg syscall (freebsd-386), const ImplementsGetwd = false
pkg syscall (freebsd-386), const O_CLOEXEC = 0
pkg syscall (freebsd-386), func Fchflags(string, int) error