[suggestion] make use of structuredClone

[jimmywarting]

Describe the problem

not a actual problem...

Describe the proposed solution

I'm just looking tough the code and looking for anything i can help contribute with, i know nothing about how the internal core works or if it is even viable.
but i see code like this with a custom clone function:

svelte/packages/svelte/src/compiler/utils/clone.js

Line 6 in 5439714

export function clone(val) {

One suggestion is to use the available structuredClone whenever it exist or not. that way your own fn can be GC and will instead use the native one, that probably is also much faster? haven't bench tested it...

so my suggestion is to do something along the lines of:

export const clone = globalThis.structuredClone || function clone() { ...

Alternatives considered

the native structuredClone can clone more stuff, i'm not just sure yet what you are cloning but basically everything that can be stored in IndexedDB can be cloned deeply. it will include things such as date, regex, file, blobs, file handles and more.

Importance

nice to have

[Conduitry]

structuredClone is a lot slower than the library that this was forked from - lukeed/klona#39 - so we don't want to use that even if it is available.

[jimmywarting]

uh. did not know that it was a lot slower. okey then... that's fine