Errors vs Exception in stdio

Just two minor tweaks:

The first is to change the ranges `byChunk` and `LockingTextReader` to throw `RangeError`s in non-release instead of doing an enforce all the time.

The second is to change File to throw an `OutOfMemoryError` instead of an exception.

I didn't actually do the test for `byLine`, because empty has (invisible) side-effects, so I didn't want to introduce any change in behavior release/non-release.