Add benchmarks for writeOutPoint.

This commit adds a benchmark for the writeOutPoint function.

bench_test.go

@@ -112,3 +112,15 @@ func BenchmarkWriteVarStr10(b *testing.B) {
 		btcwire.TstWriteVarString(ioutil.Discard, 0, "test012345")
 	}
 }
+
+// BenchmarkWriteOutPoint performs a benchmark on how long it takes to write a
+// transaction output point.
+func BenchmarkWriteOutPoint(b *testing.B) {
+	op := &btcwire.OutPoint{
+		Hash:  btcwire.ShaHash{},
+		Index: 0,
+	}
+	for i := 0; i < b.N; i++ {
+		btcwire.TstWriteOutPoint(ioutil.Discard, 0, 0, op)
+	}
+}

internal_test.go

@@ -102,3 +102,9 @@ func TstWriteBlockHeader(w io.Writer, pver uint32, bh *BlockHeader) error {
 func TstReadMessageHeader(r io.Reader) (*messageHeader, error) {
 	return readMessageHeader(r)
 }
+
+// TstWriteOutPoint makes the internal writeOutPoint function available to the
+// test package.
+func TstWriteOutPoint(w io.Writer, pver uint32, version uint32, op *OutPoint) error {
+	return writeOutPoint(w, pver, version, op)
+}