With only a single getNativeCall on DynamicMethod, we have up to
now only been able to publish and bind to one native signature
at indy call sites. Because multiple-arity core methods are
bound to Ruby using Java reflection, the signature that wins is
not predictable and may not be the one most commonly used by
callers.

This patch attempts to bypass the one nativeCall and attempt to
directly bind arguments straight through every time, falling back
on the one lucky nativeCall logic if a direct binding is not
possible.

Tried to put this elsewhere but with modules it's hard to have a
classpath class extend a module class and be accessible.

We could support more arities here, but it is difficult to predict
whether that might bind methods that should not be bound (e.g. if
a multiple-arity method had one common uber method with > 3 args it
would be bound, skipping the annotated arities). In order to land
this without introducing too much complexity, I'm limiting it to
arities <= 3.

There may be some overhead from trying and failing to acquire a
specific-arity target repeatedly. I will be refactoring the indy
binding logic to live close to (or inside) the DynamicMethod types
in order to let them slowly cache all arities with any handle
adaptations necessary. This will eliminate the extra overhead by
failing to find a given arity exactly once.