lib: add SafeSet.prototype.toUnsafeSet

[ljharb]

This should help with #57688 and others.

[codecov]

Codecov Report

Attention: Patch coverage is 33.33333% with 4 lines in your changes missing coverage. Please review.

Project coverage is 90.23%. Comparing base (1c2d98d) to head (fe02c30).
Report is 27 commits behind head on main.

Files with missing lines	Patch %	Lines
lib/internal/per_context/primordials.js	33.33%	4 Missing ⚠️

Additional details and impacted files

@@ Coverage Diff @@## main #57723 +/- ##
=======================================
Coverage 90.22% 90.23% =======================================
Files 630 630 Lines 185073 185079 +6 Branches 36222 36222 =======================================
+ Hits 166990 166998 +8 + Misses 11044 11040 -4 - Partials 7039 7041 +2 

Files with missing lines	Coverage Δ
lib/internal/per_context/primordials.js	98.66% <33.33%> (-0.53%)	⬇️

... and 22 files with indirect coverage changes

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[aduh95]

Can we write tests that validates no user-code would be run? I think this can be simplified to

Suggested change

	constset=newSet();
	this.forEach((value)=>primordials.SetPrototypeAdd(set,value));
	returnset;
	returnnewSet(this);

(given the triviality of the implementation, I wonder if it actually makes sense to add a method for that)

[ljharb]

Sure! I couldn't find anywhere SafeSet is already tested, so i'm not sure where to add them - any suggestions?

I guess this is a valid simplification since it has a safe [Symbol.iterator] on it, in which case you're right, it's probably not needed. I was assuming add-at-construction-time wasn't an option.

[ljharb]

Closing, given #57723 (comment)