Fix matches with dyn regexp

Author: antonmedv

vm/vm.go

@@ -209,8 +209,7 @@ func (vm *VM) Run() interface{} {
 		case OpMatches:
 			b := vm.pop()
 			a := vm.pop()
-
-			match, err := regexp.MatchString(a.(string), b.(string))
+			match, err := regexp.MatchString(b.(string), a.(string))
 			if err != nil {
 				panic(err)
 			}

vm/vm_test.go

@@ -127,6 +127,14 @@ func TestRun(t *testing.T) {
 			`String matches "s.+"`,
 			true,
 		},
+		{
+			`String matches ("^" + String + "$")`,
+			true,
+		},
+		{
+			`"foobar" contains "bar"`,
+			true,
+		},
 		{
 			`(0..10)[5]`,
 			int64(5),