testing: report coverage per function

[davecheney]

Feature request: 

Would it be possible to add a mode to go test -cover similar to gocov's report mode?

The goal is to report coverage on a per function basis so you can see where your
coverage is lacking. Something like this:

lucky(~/go/src/pkg/crypto/md5) % gocov test | gocov report
ok      crypto/md5      0.016s

crypto/md5/md5.go                digest.Write            100.00% (20/20)
crypto/md5/md5.go                digest.Reset            100.00% (6/6)
crypto/md5/md5.go                Sum                     100.00% (4/4)
crypto/md5/md5.go                digest.Sum              100.00% (3/3)
crypto/md5/md5.go                New                     100.00% (3/3)
crypto/md5/md5.go                init                    100.00% (1/1)
crypto/md5/md5.go                digest.Size             100.00% (1/1)
crypto/md5/md5.go                digest.checkSum         94.74% (18/19)
crypto/md5/md5.go                digest.BlockSize        0.00% (0/1)
crypto/md5/md5block_decl.go      block                   0.00% (0/0)
crypto/md5                       ----------------        96.55% (56/58)

[robpike]

Comment 2:

This issue was closed by revision golang/tools@4622486.

Status changed to Fixed.