Extend InvalidPatternSyntax to catch regex "|" (maybe also in replaceAll)

This looks pretty low value: I see ~5 instances of `split("|")` in submitted Google code and ~2 instances of `replaceAll("|", ...)`.

The best argument for the check is that most programmers probably catch the problem in development, possibly after beating their heads against the wall for a while. Maybe you can judge that from your experience with `split(".")`?

(Currently, `InvalidPatternSyntax` handles only `split(".")`, with no handling of `"|"` or `replaceAll`.)