v-attr only takes one attribute when used with globals

[ayamflow]

I made a fiddle here. Not a big issue, since the bottom solution works, but wanted to give you a hint ;)

Open the console or inspect the DOM to see that the first input render only the min attribute, while the second input correctly renders min and max.

[yyx990803]

Interesting... actually, Math is the only global symbol that I explicitly allowed in the expression parser, but when the expression is a simple keypath, Vue uses a faster keypath parser, which treats Math as a path segment. I've added a check for this special case in 3ea564b.