proposal: syscall: reconsider entire package

[mikioh]

So far syscall package holds tons of constants, a bit abstracted and raw functions that
wrap syscalls especially for networking stuff.

E.g.,
Constants assigned by IANA (IPPROTO, IFType,), other standard bodies (could be moved
into each specific package)
Set/Getsockopt for Windows
Set/GetsockoptInt,Facilites for Unix variants
Routing sockets, constants for BSD variants
Netlink sockets, constants for Linux

We can reconsider the package shape even under the Go 1 contract.
(and make things easy for bridging btw Go1 and Go2.)

[bradfitz]

Comment 1:

Labels changed: added longterm, go2, removed priority-triage.

Status changed to Accepted.

[rsc]

Comment 2:

Labels changed: added repo-main.

[rsc]

Comment 3:

Labels changed: added release-none.

[mikioh]

Comment 4:

Now I feel that syscall should keep syscall.Syscall-like functions in and constants and
numbers out.

Labels changed: removed go2.

[mikioh]

Comment 5:

Issue #2999 has been merged into this issue.