Call defineProperties in bulk with list of descriptors for performance

[airhorns]

We're already mutating the descriptors here, may as well define em all in bulk instead of one at a time on a new object

[codspeed-hq]

CodSpeed Performance Report

Merging #112 will improve performances by 34.5%

_{Comparing faster-self-define (91012b7) with faster-self-define (55289a4)}

Summary

⚡ 2 improvements
✅ 9 untouched benchmarks

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
⚡	instantiating a large union	62.5 µs	52.9 µs	+18.05%
⚡	accessing unmemoized null property of a class model	12.2 µs	9.1 µs	+34.5%