go.mod: update to 'go 1.17'

This enables module graph pruning for modules that depend on x/build,
and lazy loading within x/build proper.

It may also help somewhat with build timeouts for small Playground
programs that import from x/build, such as the one observed in
https://play.golang.org/p/Jj_dmqq6de0.

Change-Id: Ic963ebf8d6b3d1580e9c11012ce37a8d22e6ac11
Reviewed-on: https://go-review.googlesource.com/c/build/+/363494
Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>

go.mod

@@ -1,6 +1,6 @@
 module golang.org/x/build
 
-go 1.16
+go 1.17
 
 require (
 	cloud.google.com/go v0.88.0
@@ -50,3 +50,42 @@ require (
 	gopkg.in/inf.v0 v0.9.1
 	grpc.go4.org v0.0.0-20170609214715-11d0a25b4919
 )
+
+require (
+	github.com/alecthomas/template v0.0.0-20190718012654-fb15b899a751 // indirect
+	github.com/alecthomas/units v0.0.0-20190924025748-f65c72e2690d // indirect
+	github.com/anmitsu/go-shlex v0.0.0-20200514113438-38f4b401e2be // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/census-instrumentation/opencensus-proto v0.2.1 // indirect
+	github.com/cespare/xxhash/v2 v2.1.1 // indirect
+	github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e // indirect
+	github.com/google/go-querystring v1.0.0 // indirect
+	github.com/hashicorp/errwrap v1.0.0 // indirect
+	github.com/hashicorp/go-multierror v1.1.0 // indirect
+	github.com/hashicorp/golang-lru v0.5.4 // indirect
+	github.com/jackc/chunkreader/v2 v2.0.1 // indirect
+	github.com/jackc/pgerrcode v0.0.0-20201024163028-a0d42d470451 // indirect
+	github.com/jackc/pgio v1.0.0 // indirect
+	github.com/jackc/pgpassfile v1.0.0 // indirect
+	github.com/jackc/pgproto3/v2 v2.1.1 // indirect
+	github.com/jackc/pgservicefile v0.0.0-20200714003250-2b9c44734f2b // indirect
+	github.com/jackc/pgtype v1.8.1 // indirect
+	github.com/jackc/puddle v1.1.3 // indirect
+	github.com/jmespath/go-jmespath v0.4.0 // indirect
+	github.com/jstemmer/go-junit-report v0.9.1 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.1 // indirect
+	github.com/prometheus/client_golang v1.9.0 // indirect
+	github.com/prometheus/client_model v0.2.0 // indirect
+	github.com/prometheus/common v0.15.0 // indirect
+	github.com/prometheus/procfs v0.2.0 // indirect
+	github.com/prometheus/statsd_exporter v0.20.0 // indirect
+	github.com/sirupsen/logrus v1.8.1 // indirect
+	go.uber.org/atomic v1.6.0 // indirect
+	golang.org/x/lint v0.0.0-20210508222113-6edffad5e616 // indirect
+	golang.org/x/mod v0.4.2 // indirect
+	golang.org/x/tools v0.1.5 // indirect
+	golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1 // indirect
+	google.golang.org/appengine v1.6.7 // indirect
+	gopkg.in/alecthomas/kingpin.v2 v2.2.6 // indirect
+	gopkg.in/yaml.v2 v2.4.0 // indirect
+)