mishoo/UglifyJS — pull request #340 by FarSeeing (2012-03-19 07:58:17+00:00)
Title: Storten Number and Infinity constants

Add unsafe shortcuts for Number constants (idea taken from #262).

```Number.POSITIVE_INFINITY``` and ```Infinity``` to ```1/0```,
```Number.NEGATIVE_INFINITY``` and ```-Infinity``` to ```-1/0```,
```Number.NaN``` to ```NaN```

Transformations are only made if the are no ```Infinity``` or ```NaN``` in scope, but still there is a curios thing:
using them as array index/property name also gets affected. It (possibly) can lead to a problem, but current browsers handle it correctly:

```
>>> x = {Infinity: 3}
Object { Infinity=3}
>>> x[Infinity]
3
>>> x[1/0]
3
```