indifier: a tool for transforming JVM bytecode to use invokedynamic.

The goal here is to provide a utility for converting exsting JVM bytecode to use invokedynamic rather than pre-Java 7 mechanisms for calling methods, accessing fields, etc.

The initial use case I have in mind is for JRuby to transform all dyncalls from Java to Ruby into invokedynamic calls, so they can be done in an inlinable, optimizable way. Other use cases would be modifying Java code to treat calculated static final values as actually constant, hooking into method calls, field accesses, and array accesses, and implementing simple dynamic invocation with normal Java code.