Generate smaller bytecode when using Ruby type on implemented Java Interface + Benchmark

[original-brownbear]

It seems when compiling Ruby implementations of Java interfaces, we were generating bytecode that runs any non-primitive type through convertJavaToUsableRubyObject.
This seems unnecessary to me if we know that we're dealing with an IRubyObject type of argument => we can save that call and the loading of the Ruby runtime argument, right?

I included the benchmark I used to verify that this comes with a positive performance impact (for me it showed about a 5% speed-up).

[kares]

totally makes sense - thanks for digging throught these bits, there's probably a lot of 💎 to be found :)

[headius]

👍 looks good. There's a lot of gems hidden in interface impl and concrete subclass logic:

• Use indy to optimize method lookups, dispatch, and type conversion
• Move more logic to utility methods

This is a good start :-)