all: update vendored dependencies during Go 1.16 development

all: update vendored dependencies during Go 1.16 development

The Go 1.16 development cycle has started. This is the time to update
all golang.org/x/... module versions that contribute packages to the
std and cmd modules in the standard library to latest master versions.

Those versions have already gone through code review, and now they
will undergo additional testing during the development period.
If there are new issues in these dependencies discovered, we have
development period to deal with that. We will do this update once
more at the end of the development cycle, by the code freeze, and
so doing it now will make that update smaller and safer.

Overall, this change will help us build confidence that the
Go 1.16 release and its selected dependencies will be robust.

Also increment the Go language version to 1.16 in standard library
go.mod files.

This change was created with a program from CL 256357 patch set 1
(which updates golang.org/x modules only) and the bundle tool at
CL 255053 patch set 1:

	$ updatestd -goroot=$HOME/gotip -branch=master
	> go version
	go version devel +eda1d40544 Mon Sep 21 16:50:07 2020 +0000 darwin/amd64
	> go env GOROOT
	/Users/dmitshur/gotip
	> go version -m /Users/dmitshur/go/bin/bundle
	/Users/dmitshur/go/bin/bundle: go1.15.2
		path	golang.org/x/tools/cmd/bundle
		mod	golang.org/x/tools	(devel)	 # CL 255053 PS 1
		dep	golang.org/x/mod	v0.3.0	h1:RM4zey1++hCTbCVQfnWeKs9/IEsaBLA8vTkd0WVtmH4=
		dep	golang.org/x/xerrors	v0.0.0-20200804184101-5ec99f83aff1	h1:go1bK/D/BFZV2I8cIQd1NKEZ+0owSTG1fDTci4IqFcE=

	updating module cmd in /Users/dmitshur/gotip/src/cmd
	skipping github.com/chzyer/logex (out of scope, it's not a golang.org/x dependency)
	skipping github.com/chzyer/readline (out of scope, it's not a golang.org/x dependency)
	skipping github.com/chzyer/test (out of scope, it's not a golang.org/x dependency)
	skipping github.com/google/pprof (out of scope, it's not a golang.org/x dependency)
	skipping github.com/ianlancetaylor/demangle (out of scope, it's not a golang.org/x dependency)
	skipping github.com/yuin/goldmark (out of scope, it's not a golang.org/x dependency)
	skipping rsc.io/pdf (out of scope, it's not a golang.org/x dependency)
	> go mod edit -go=1.16
	> go get -d golang.org/x/arch@b19915210f009e139b20abfd6a6052c7acc1f445 golang.org/x/crypto@5c72a883971a4325f8c62bf07b6d38c20ea47a6a golang.org/x/mod@ce943fd02449f621243c9ea6e64098e84752b92b golang.org/x/net@62affa334b73ec65ed44a326519ac12c421905e3 golang.org/x/sync@6e8e738ad208923de99951fe0b48239bfd864f28 golang.org/x/sys@af09f7315aff1cbc48fb21d21aa55d67b4f914c5 golang.org/x/text@a8b4671254579a87fadf9f7fa577dc7368e9d009 golang.org/x/tools@d647fc2532668b2b75a92f468487b8085e6ed58b golang.org/x/xerrors@5ec99f83aff198f5fbd629d6c8d8eb38a04218ca
	go: golang.org/x/sys af09f7315aff1cbc48fb21d21aa55d67b4f914c5 => v0.0.0-20200918174421-af09f7315aff
	go: golang.org/x/text a8b4671254579a87fadf9f7fa577dc7368e9d009 => v0.3.4-0.20200826142016-a8b467125457
	go: golang.org/x/tools d647fc2532668b2b75a92f468487b8085e6ed58b => v0.0.0-20200918232735-d647fc253266
	go: golang.org/x/net 62affa334b73ec65ed44a326519ac12c421905e3 => v0.0.0-20200904194848-62affa334b73
	go: golang.org/x/crypto 5c72a883971a4325f8c62bf07b6d38c20ea47a6a => v0.0.0-20200820211705-5c72a883971a
	go: golang.org/x/arch b19915210f009e139b20abfd6a6052c7acc1f445 => v0.0.0-20200826200359-b19915210f00
	go: golang.org/x/xerrors 5ec99f83aff198f5fbd629d6c8d8eb38a04218ca => v0.0.0-20200804184101-5ec99f83aff1
	> go mod tidy
	> go mod vendor

	updating module std in /Users/dmitshur/gotip/src
	> go mod edit -go=1.16
	> go get -d golang.org/x/crypto@5c72a883971a4325f8c62bf07b6d38c20ea47a6a golang.org/x/net@62affa334b73ec65ed44a326519ac12c421905e3 golang.org/x/sys@af09f7315aff1cbc48fb21d21aa55d67b4f914c5 golang.org/x/text@a8b4671254579a87fadf9f7fa577dc7368e9d009 golang.org/x/tools@d647fc2532668b2b75a92f468487b8085e6ed58b
	go: golang.org/x/crypto 5c72a883971a4325f8c62bf07b6d38c20ea47a6a => v0.0.0-20200820211705-5c72a883971a
	go: golang.org/x/text a8b4671254579a87fadf9f7fa577dc7368e9d009 => v0.3.4-0.20200826142016-a8b467125457
	go: golang.org/x/sys af09f7315aff1cbc48fb21d21aa55d67b4f914c5 => v0.0.0-20200918174421-af09f7315aff
	go: golang.org/x/tools d647fc2532668b2b75a92f468487b8085e6ed58b => v0.0.0-20200918232735-d647fc253266
	> go mod tidy
	> go mod vendor

	updating bundles in /Users/dmitshur/gotip/src
	> go generate -run=bundle std cmd

Other non-golang.org/x module dependencies (pprof and demangle)
still need to be updated in a future CL.

For #36905.

Change-Id: I83a350bf8714ebc249284c0d69abe4941700565e
Reviewed-on: https://go-review.googlesource.com/c/go/+/255860
Reviewed-by: Bryan C. Mills <bcmills@google.com>
Trust: Dmitri Shuralyov <dmitshur@golang.org>