proposal: net: Add support for HTTP/3(QUIC).

[CodingByteFly]

What version of Go are you using (go version)?

$ go version 
go version go1.13.5 windows/amd64

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
set GO111MODULE=on
set GOARCH=amd64
set GOBIN=
set GOCACHE=F:\GoLang\GOCACHE
set GOENV=D:\LOVEL\Documents\GoLang\GOENV\env
set GOEXE=.exe
set GOFLAGS=
set GOHOSTARCH=amd64
set GOHOSTOS=windows
set GONOPROXY=
set GONOSUMDB=
set GOOS=windows
set GOPATH=F:\GoLang\GOPATH
set GOPRIVATE=
set GOPROXY=https://goproxy.cn,direct
set GOROOT=D:\Program-Files\GoLang
set GOSUMDB=sum.golang.org
set GOTMPDIR=F:\GoLang\GOTMPDIR
set GOTOOLDIR=D:\Program-Files\GoLang\pkg\tool\windows_amd64
set GCCGO=gccgo
set AR=ar
set CC=gcc
set CXX=g++
set CGO_ENABLED=1
set GOMOD=NUL
set CGO_CFLAGS=-g -O2
set CGO_CPPFLAGS=
set CGO_CXXFLAGS=-g -O2
set CGO_FFLAGS=-g -O2
set CGO_LDFLAGS=-g -O2
set PKG_CONFIG=pkg-config
set GOGCCFLAGS=-m64 -mthreads -fmessage-length=0 -fdebug-prefix-map=F:\GoLang\GOTMPDIR\go-build781419050=/tmp/go-build -gno-record-gcc-switches

What did you do?

Web develop

What did you expect to see?

As we known, HTTP/3(QUIC) is better than HTTP/2.
But when I

import "net"

I found that it can't support HTTP/3(QUIC). I think it is bad for the development of HTTP/3(QUIC). Go originated in Google, and HTTP/3(QUIC) was also developed by Google. I think if the stardard library of Go can support HTTP/3(QUIC), it will benefit for the development of Go and HTTP/3(QUIC).

What did you see instead?

As we known, HTTP/3(QUIC) is better than HTTP/2.
But when I

import "net"

I found that it can't support HTTP/3(QUIC).

[mvdan]

HTTP/3 is only a draft as of December 2019, right? Following what was done for HTTP/2, it seems to me like the work should happen in the x/net repo first, and become part of the standard library once the final version is out.

[mvdan]

Also, this is a duplicate of #32204.