[Bug]: Swift 6 doesn't work on Android 7-9

[finagolfin]

Problem description

The Swift 6 stdlib added a thread-local variable for the first time to an inline method defined in one of its C++ headers (the Swift stdlib is written in a mix of Swift and C++), but the Swift compiler probably doesn't pass the Android API when compiling that C++ method, so it wrongly tries to use native thread-local storage with Android API 24, even though Android didn't support that till API 29.

I will look into a fix and update the compiler once I have one, in the meantime, this is to let everyone know this package is currently expected to fail on older Android devices.

What steps will reproduce the bug?

Running the Swift toolchain on Android 7-9 makes it segfault

What is the expected behavior?

Running fine, as it does on Android 10 or later

System information

Saw this on an old tablet running Android 9 AArch64 and the x86_64 emulator on github Actions