support basic properties of UILayoutGuide.

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    UIView *v = [[UIView alloc] initWithFrame:CGRectZero];
    v.backgroundColor = UIColor.brownColor;
    [self.view addSubview:v];
    [v mas_makeConstraints:^(MASConstraintMaker *make) {
        make.center.mas_equalTo(self.view);
        make.size.mas_equalTo(CGSizeMake(30, 30));
    }];

    UILayoutGuide *guide = [[UILayoutGuide alloc] init];
    [self.view addLayoutGuide:guide];
    [guide.widthAnchor constraintEqualToConstant:10].active = YES;
    [guide.heightAnchor constraintEqualToConstant:0].active = YES;
    [guide.centerYAnchor constraintEqualToAnchor:v.centerYAnchor].active = YES;
    [guide.leftAnchor constraintEqualToAnchor:v.rightAnchor constant:0].active = YES;

    UIView *v2 = [[UIView alloc] initWithFrame:CGRectZero];
    v2.backgroundColor = UIColor.orangeColor;
    [self.view addSubview:v2];
    [v2 mas_makeConstraints:^(MASConstraintMaker *make) {
        make.left.mas_equalTo(guide.mas_right);
        make.centerY.mas_equalTo(self.view);
        make.size.mas_equalTo(CGSizeMake(30, 30));
    }];

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#594