`main()` function used to be needed to support dart, since dart
Does not allow top level statements. Since we no longer use dart
The need for `main()` has been removed.
In preparation for `Basel` and standardized way of running tests
we are removing `main()`
PR Close#21053
Each node now has two index: nodeIndex and checkIndex.
nodeIndex is the index in both the view definition and the view data.
checkIndex is the index in in the update function (update directives and update
renderer).
While nodeIndex and checkIndex have the same value for now, having both of them
will allow changing the structure of view definition after compilation (ie for
runtime translations).
