Add new Foundation libraries to SwiftRuntimeLibsOrdered

[jmschonfeld]

Now that Foundation has added a handful of new libraries to the build that are linked from Foundation itself, we're seeing a handful of build logs that contain contents like the following:

... -lFoundationInternationalization -lFoundationEssentials -lFoundationInternationalization -lFoundationEssentials -lstdc++ -lswiftCxx -lswiftCxxStdlib -lstdc++ -lswiftCxx -lswiftCxxStdlib -lstdc++ -lswiftCxx -lswiftCxxStdlib -lstdc++ -lswiftCxx -lswiftCxxStdlib -lFoundationInternationalization -lFoundationEssentials -lFoundationInternationalization -lFoundationEssentials -lFoundationInternationalization -lFoundationEssentials -lswift_Differentiation -lFoundationInternationalization -lFoundationEssentials -lFoundationInternationalization -lFoundationEssentials -lFoundationInternationalization -lFoundationEssentials -lFoundationInternationalization -lFoundationEssentials ...

Per swiftlang/swift-foundation#872, this list seems to be used to deduplicate linked libraries for common libraries. This change adds the new Foundation dynamic libraries (FoundationEssentials, FoundationInternationalization, and _FoundationICU) along with swiftSynchronization (which Foundation also links now) to this list for deduplication to help minimize the issues caused by these repeated link flags.

(I'm not extremely familiar with this list, but it seems that since Foundation is already there we should add the new Foundation libraries, however feel free to let me know if we shouldn't do this or if there's a different change that should be made)

[jmschonfeld]

@swift-ci please smoke test

[finagolfin]

I think you can remove the icu libs now: those are no longer built or shipped separately.

[finagolfin]

This is now swiftRegexBuilder.

[finagolfin]

As long as we're here, might as well update this list for 6.1. Some more candidates for addition: swift_Builtin_float, swift_Differentiation, swiftDistributed, swiftObservation, swift_Volatile, Testing.

@stephentyrone, @ktoso, @grynspan, @al45tair, wdyt, should we add any of those?

[grynspan]

I honestly don't know. :)

[finagolfin]

@grynspan, try this: find a large project with many Testing test files, then run swift build --build-tests -v on linux. Does the last link command building the test runner have one -lTesting or many?

[grynspan]

Ah, yes, one per file. So sounds like we should add Testing as you've suggested.

[finagolfin]

Pinging @gwynne and @compnerd too, in case you have any input.

[finagolfin]

@al45tair and @FranzBusch, mind pushing this change through to completion and into Swift 6? We are going to see a regression with a ton of repeated linker flags on linux and other Unix platforms otherwise.

It looks like everybody went on summer vacation in the last couple weeks when this was proposed, but with the Swift 6 release likely coming in the next month, we should get this in.

[compnerd]

Ouch, this is a great catch! Definitely something to consider pulling into 6.0.

CC: @parkera

[finagolfin]

Thanks, @compnerd, do you have an opinion on which other of the new runtime libraries listed above should also be de-duplicated?

[compnerd]

I'd say that Testing is a good idea to add to the list, the other ones don't seem as important.

[finagolfin]

Alright, if someone would go ahead and merge, @jmschonfeld doesn't seem to be active lately, so I went ahead and submitted #76224 with my remaining suggestions for this pull, so we can get those in separately.

[jmschonfeld]

Sorry for the delay @finagolfin! I'll go ahead and merge this one, thanks for the followup PR!