try to reduce binary size

[madelynnblue]

https://github.com/jondot/goweight says:

  9.9 MB github.com/cockroachdb/cockroach/pkg/roachpb
  7.0 MB github.com/cockroachdb/cockroach/vendor/github.com/DataDog/zstd
  6.2 MB github.com/cockroachdb/cockroach/pkg/sql/sem/tree
  4.5 MB github.com/cockroachdb/cockroach/pkg/sql/sem/builtins
  4.2 MB github.com/cockroachdb/cockroach/pkg/sql/sqlbase
  3.4 MB github.com/cockroachdb/cockroach/pkg/sql/parser
  3.4 MB net/http
  3.2 MB github.com/cockroachdb/cockroach/vendor/github.com/Shopify/sarama
  3.0 MB runtime
  2.5 MB github.com/cockroachdb/cockroach/vendor/github.com/gogo/protobuf/proto
  1.8 MB github.com/cockroachdb/cockroach/vendor/github.com/gogo/protobuf/types
  1.7 MB github.com/cockroachdb/cockroach/vendor/golang.org/x/net/http2
  1.7 MB github.com/cockroachdb/cockroach/vendor/github.com/lightstep/lightstep-tracer-go/thrift_0_9_2/lib/go/thrift
  1.7 MB github.com/cockroachdb/cockroach/vendor/github.com/apache/thrift/lib/go/thrift
  1.7 MB net
  1.6 MB github.com/cockroachdb/cockroach/vendor/github.com/golang/protobuf/proto
  1.4 MB github.com/cockroachdb/cockroach/vendor/golang.org/x/text/collate
  1.4 MB github.com/cockroachdb/cockroach/vendor/github.com/aws/aws-sdk-go/aws/endpoints
  1.4 MB reflect
  1.2 MB github.com/cockroachdb/cockroach/vendor/golang.org/x/sys/unix
  1.2 MB github.com/cockroachdb/cockroach/vendor/google.golang.org/grpc
  1.1 MB github.com/cockroachdb/cockroach/pkg/internal/client
  1.0 MB github.com/spf13/pflag
  1.0 MB github.com/cockroachdb/cockroach/vendor/github.com/prometheus/client_golang/prometheus
  991 kB github.com/cockroachdb/cockroach/pkg/util/json
  975 kB github.com/cockroachdb/cockroach/vendor/gopkg.in/yaml.v2
...