Faster constructor

[airhorns]

On top of #65

15% improvement by removing a megamorphic call to the fast instantiator function! Yeesh!

On perf-improvements:

❯ node dist/bench/create-many-different-roots.js
instantiating a large root x 3,258 ops/sec ±0.84% (100 runs sampled)
instantiating a small root x 10,573,575 ops/sec ±0.21% (92 runs sampled)
instantiating a diverse root x 464,002 ops/sec ±0.15% (100 runs sampled)

On this branch:

❯ node dist/bench/create-many-different-roots.js
instantiating a large root x 3,851 ops/sec ±0.29% (97 runs sampled)
instantiating a small root x 15,595,988 ops/sec ±0.46% (99 runs sampled)
instantiating a diverse root x 582,571 ops/sec ±0.65% (99 runs sampled)

[airhorns]

This call was megamorphic before -- all the MQT classes subclass this one, and then this class ends up calling the instantiator. Because they all share the same parent class, this callsite is shared among all of em! Instead of generating this function, we can instead generate a child class that hardcodes the instantiation logic right in its constructor. Super duper monomorphic!

[thegedge]

So simple, but so effective!

[thegedge]

Majestic!

[thegedge]

So simple, but so effective!