Allow designated initialization of struct

[ryuukk_]

https://x.com/SebAaltonen/status/1848311998376738892/

https://x.com/FlohOfWoe/status/1848357742240518436

https://x.com/SebAaltonen/status/1848336276308554192

https://x.com/FlohOfWoe/status/1848355671554535764

If you want to attract talents, you have to provide them with the 
tools to be at least as productive and efficient as with C

I read, learn and get inspiration from these kind of people

I get rewarded as a result, relatively fast code (i'm still 
improving as i learn), ~0.4s clean build, and 300kb WASM file