refactor to use reg.Set

reg/set_test.go

@@ -0,0 +1,12 @@
+package reg
+
+import "testing"
+
+func TestFamilyRegisterSets(t *testing.T) {
+	fs := []*Family{GeneralPurpose, SIMD}
+	for _, f := range fs {
+		if len(f.Set()) != len(f.Registers()) {
+			t.Fatal("family set and list should have same size")
+		}
+	}
+}