math/bits: add examples for OnesCount functions

Change-Id: Ie673f9665825a40281c2584d478ba1260f725856
Reviewed-on: https://go-review.googlesource.com/53357
Run-TryBot: Chris Broadfoot <cbro@golang.org>
Reviewed-by: Chris Broadfoot <cbro@golang.org>

src/math/bits/example_test.go

@@ -36,3 +36,43 @@ func ExampleLeadingZeros64() {
 	// 64
 	// 63
 }
+
+func ExampleOnesCount() {
+	fmt.Printf("%b\n", 14)
+	fmt.Println(bits.OnesCount(14))
+	// Output:
+	// 1110
+	// 3
+}
+
+func ExampleOnesCount8() {
+	fmt.Printf("%b\n", 14)
+	fmt.Println(bits.OnesCount8(14))
+	// Output:
+	// 1110
+	// 3
+}
+
+func ExampleOnesCount16() {
+	fmt.Printf("%b\n", 14)
+	fmt.Println(bits.OnesCount16(14))
+	// Output:
+	// 1110
+	// 3
+}
+
+func ExampleOnesCount32() {
+	fmt.Printf("%b\n", 14)
+	fmt.Println(bits.OnesCount32(14))
+	// Output:
+	// 1110
+	// 3
+}
+
+func ExampleOnesCount64() {
+	fmt.Printf("%b\n", 14)
+	fmt.Println(bits.OnesCount(14))
+	// Output:
+	// 1110
+	// 3
+}