cmd/vet: remove Peek from methods check

[josharian]

vet's methods check ensures that methods with a canonical name have the right signature. This includes:

	"Peek":          {[]string{"=int"}, []string{"[]byte", "error"}},                   // image.reader (matching bufio.Reader)

But it's not clear to me why the unexported image.reader interface is important enough to set the canonical interpretation of Peek.

I see three Peeks in the standard library:

// bufio
func (b *Reader) Peek(n int) ([]byte, error)

// cmd/internal/obj
func (a *AsmBuf) Peek(i int) byte

// text/scanner
func (s *Scanner) Peek() rune

Of these, only bufio.Reader matches. Another Peek that comes to mind is from Russ's article Off to the Races:

// Peek reads and returns the word at address addr.
func (m *Mem) Peek(addr uintptr) uintptr

I think we should remove Peek from the list of canonical method names.

The CL is trivial; this issue is to ask for approval.

@robpike

[robpike]

Fine with me.

[gopherbot]

CL https://golang.org/cl/38722 mentions this issue.