Support compiling data-v-123 into data-v="123"

[yangdan8]

Since some projects need to write styles to override the styles of components generated with a scopeId, for example:
.xxx[data-v-123]{color:red;}

However, the generated scopeId changes every time the component version is updated (e.g., it changes to 456), which makes it necessary to modify the styles like this:
.xxx[data-v-456]{color:red;}

Because it is not possible to implement .xxx[data-v-*]{color:red;} with CSS, a new requirement is proposed:
Can we support compiling it into data-v="123"?

If so, we can use it like this:
.xxx[data-v]{color:red;}

---中文描述如下---

.xxx[data-v-123]{color:red;}
但每次更新组件版本后生成的scopeId不同，比如变成了456，导致要修改样式，如
.xxx[data-v-456]{color:red;}
因为无法用css实现.xxx[data-v-*]{color:red;}，所以提出新需求：
是否可以支持编译data-v="123"？
那就可以这么用了：
.xxx[data-v]{color:red;}

[Justineo]

1. data-v-xxx was never meant to be used as a CSS targeting hook.
2. The proposed change is fundamentally incorrect because [data-v] would match all scoped elements and I cannot imagine how that would work.

[yangdan8]

The original usage was [data-v-123], while the new usage is [data-v="123"]