Msgsize and msgp:size ignore directive

[pierrec]

Hello,

When the "msg:size ignore Type" directive is used the tests still contain a reference to the Msgsize method, which does not exist.

For instance:

//msgp:size ignore Type
package main

type Type struct {
  A int
}

func main() {
  t := &Type{}
  _ = t
}

generates the following test file:

package main

// NOTE: THIS FILE WAS PRODUCED BY THE
// MSGP CODE GENERATION TOOL (github.com/tinylib/msgp)
// DO NOT EDIT

import (
    "bytes"
    "testing"

    "github.com/tinylib/msgp/msgp"
)

func TestEncodeDecodeType(t *testing.T) {
    v := Type{}
    var buf bytes.Buffer
    msgp.Encode(&buf, &v)

    m := v.Msgsize()
    if buf.Len() > m {
        t.Logf("WARNING: Msgsize() for %v is inaccurate", v)
    }

    vn := Type{}
    err := msgp.Decode(&buf, &vn)
    if err != nil {
        t.Error(err)
    }

    buf.Reset()
    msgp.Encode(&buf, &v)
    err = msgp.NewReader(&buf).Skip()
    if err != nil {
        t.Error(err)
    }
}

func BenchmarkEncodeType(b *testing.B) {
    v := Type{}
    var buf bytes.Buffer
    msgp.Encode(&buf, &v)
    b.SetBytes(int64(buf.Len()))
    en := msgp.NewWriter(msgp.Nowhere)
    b.ReportAllocs()
    b.ResetTimer()
    for i := 0; i < b.N; i++ {
        v.EncodeMsg(en)
    }
    en.Flush()
}

func BenchmarkDecodeType(b *testing.B) {
    v := Type{}
    var buf bytes.Buffer
    msgp.Encode(&buf, &v)
    b.SetBytes(int64(buf.Len()))
    rd := msgp.NewEndlessReader(buf.Bytes(), b)
    dc := msgp.NewReader(rd)
    b.ReportAllocs()
    b.ResetTimer()
    for i := 0; i < b.N; i++ {
        err := v.DecodeMsg(dc)
        if err != nil {
            b.Fatal(err)
        }
    }
}

Thank you.