parser.{Expr,Statement} publicly implementable (#7639)
parser.{Expr,Statement} publicly implementable (#7639)

* parser.{Expr,Statement} publicly implementable

Signed-off-by: Owen Diehl <b7f53a77a4950cb4aa47d9da3f442809e803fde5@gmail.com>
alileza/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,keegancsmith/prometheus,kangwoo/prometheus,keegancsmith/prometheus,alileza/prometheus,prometheus/prometheus,alileza/prometheus,keegancsmith/prometheus,GoogleCloudPlatform/prometheus,kangwoo/prometheus,prometheus/prometheus,alileza/prometheus,GoogleCloudPlatform/prometheus,kangwoo/prometheus,kangwoo/prometheus,keegancsmith/prometheus,prometheus/prometheus,prometheus/prometheus,GoogleCloudPlatform/prometheus,GoogleCloudPlatform/prometheus,alileza/prometheus,keegancsmith/prometheus