[5.3] Fix View compilation bug

[manan-jadhav]

Having {{$var['a or b']}} would generate wrong code, since the key ('a or b') contains 'or' and this or was understood as the 'or' shortcut.

Fixed the issue by improving the regex used for detecting the 'or' shortcut.

[taylorotwell]

What about situations like: {{ thorson() }} ... does that cause problems?

[manan-jadhav]

Sorry, I made a mistake in describing the problem, {{$var['thor']}} wont be a problem,
but {{$var['a or b']}} will be. Basically, having 'or' with spaces around it, like in 'a or b' will cause problems. Situations like {{thorson()}} wont be a problem since the 'or' it contains does not having spaces surrounding it. And also, there needs to be a leading '$' sign as well, which {{thorson()}} does not have.

[browner12]

TIL you can have spaces in your array key.

[manan-jadhav]

@taylorotwell should this go to 5.1 branch as well?

[fernandobandeira]

This broke things, check #16593 ...