Investigate Swift 6.2 build failures for armv7

[xtremekforever]

The CI for Swift 6.2 fails:

https://github.com/xtremekforever/swift-armhf/actions/runs/16400457920

We need to investigate why and fix the issue in main.

[xtremekforever]

This appears to be a C++ interop bug when importing Glibc. Relevant issues have been filed here:

• Glibc import fails to cross-compile with Swift SDK when .Cxx interop is enabled swiftlang/swift#83915
• Glibc cross-compilation errors with .cxx interop enabled with a 6.2 snapshot Swift SDK swiftlang/swift-package-manager#9060

This issue can remain open until the issue is resolved- hopefully for 6.2.

[xtremekforever]

The issue is fixed in main and cherry-picked to release/6.2, but we are still seeing a crash on the latest snapshot for 6.2:

https://github.com/swift-embedded-linux/armhf-debian/actions/runs/17517120669

I'll wait for a newer snapshot and see if the issue goes away.

[xtremekforever]

The final state of things is that the Cxx interop fix for Glibc is not included in Swift 6.2.0:

swiftlang/swift#84284

However, the fix is available in 6.2.1 and future versions. I'll close this now since everything seems to work except that on Swift 6.2.