RFR: 8193508: Expressions in split literals must never be optimistic

[Hannes Wallnöfer]

Please review:

Bug: https://bugs.openjdk.java.net/browse/JDK-8193508
Webrev: http://cr.openjdk.java.net/~hannesw/8193508/webrev.00/

The actual fix is quite simple: stop visiting when we encounter a split object or array literal in OptimisticTypesCalculator.

There are a few non-essential changes:
 - rename methods and fields in CodeGeneratorLexicalContext from *SplitNode to *SplitLiteral as the former is misleading (no actual SplitNodes around)
 - make sure we don’t have optimistic operations unless we generate optimistic code to avoid the situation that enabled this bug
 - add logging for split array and object nodes in Splitter
 - add some @Ignore annotations to make nodes behave in IR printer

Thanks,
Hannes