There is another expr separator
Revert "There is another expr separator"

This reverts commit 2c31a333ef0d7736e46b8ced65551c1d83da69a7.
Get rid of the expression subclasses

It's much cheaper to dentify them by a magic symbol at the beginning of the array
Yess
Remove junk
Decruft more
And now we can finally reduce the number of parsed nodes
Upver