Optional xcframework support for Linux

[vsarunas]

Re-apply #9374 which reverts #7239.

Fix Linux arm build; replacing arm64 -> aarch64; Ubuntu test passes. Fixes #9372

Prior it was failing with:

swift-package-manager/.build/aarch64-unknown-linux-gnu/debug/swift-run --package-path /tmp/Miscellaneous_LibraryEvolutionLinuxXCF.07p2Rv/TestBinary --configuration debug --build-system native --scratch-path /tmp/Miscellaneous_LibraryEvolutionLinuxXCF.07p2Rv/TestBinary/.build-test --experimental-xcframeworks-on-linux TestBinary output:
    Building for debugging...
    [0/5] Write sources
    [1/5] Write swift-version--1B491C3C2A126B95.txt
    error: emit-module command failed with exit code 1 (use -v to see invocation)
    [3/7] Emitting module TestBinary
    /tmp/Miscellaneous_LibraryEvolutionLinuxXCF.07p2Rv/TestBinary/Sources/TestBinary/Main.swift:1:8: error: no such module 'SwiftFramework'
    1 | import SwiftFramework
      |        `- error: no such module 'SwiftFramework'
    2 |
    3 | print("Latest Framework with LibraryEvolution version: \(SwiftFrameworkWithEvolution.latest)")
    [4/7] Compiling TestBinary Main.swift
    /tmp/Miscellaneous_LibraryEvolutionLinuxXCF.07p2Rv/TestBinary/Sources/TestBinary/Main.swift:1:8: error: no such module 'SwiftFramework'
    1 | import SwiftFramework
      |        `- error: no such module 'SwiftFramework'
    2 |
    3 | print("Latest Framework with LibraryEvolution version: \(SwiftFrameworkWithEvolution.latest)")
✘ Test libraryEvolutionLinuxXCFramework() failed after 2.350 seconds with 1 issue.

[vsarunas]

@daveinglis, @bkhouri - can you confirm the error you saw is the same as the one in the description?

[bkhouri]

@daveinglis, @bkhouri - can you confirm the error you saw is the same as the one in the description?

Yes. that's the same error. I was also able to reproduce the failure at-desk without this change, and this PR does not exhibit the issues.

[bkhouri]

@swift-ci test