getAddrInfo index out of bounds error

[FedericoCeratto]

sendTo() fails on a raw ICMP socket:

import net
newSocket(AF_INET, SOCK_RAW, IPPROTO_ICMP).sendTo("127.0.0.1", 0.Port, "")    

getAddrInfo in nativesockets.nim raises:

Error: unhandled exception: index out of bounds: (i:-1) <= (n:-1)  [IndexError]

[BontaVlad]

Since this could be my first ever PR for a open source project I will leave a comment here first.
I managed to fix this issue by adding a check in nativesockets.nim:getAddrInfo

let socket_port = if sockType == SOCK_RAW: "" else: $port
var gaiResult = getaddrinfo(address, socket_port, addr(hints), result)

SOCK_RAW (a socket type that does not support the concept of services)
More info can be found here
If there are more socket types that don't need a 'port' let me know.

I also changed 2 lines of code in oserr.nim:

  + if e.msg == "":
  +  e.msg = "unknown OS error"
  if additionalInfo.len > 0:
    if e.msg[^1] != '\n': e.msg.add '\n'
    e.msg.add  "Additional info: "
    e.msg.addQuoted additionalInfo
  - if e.msg == "":
  -  e.msg = "unknown OS error"

This will make raiseOSError care about additionalInfo even for errors that could not be retrieved, in the getAddrInfo example, useful error msg like gai_strerror(gaiResult) would never be shown.
Let me know if I misunderstood something. I also have could submit a PR if this is desired.

[FedericoCeratto]

@BontaVlad thanks, I successfully tested the change to getAddrInfo. I can add a test under tests/stdlib in your PR

[FedericoCeratto]

I opened PR #10210 to also add ICMPv6 - I hope you don't mind.