When `-unavailable-decl-optimization=stub` is specified, insert a call to
`_diagnoseUnavailableCodeReached()` at the beginning of the function to cause
it to trap if executed at run time.
Part of rdar://107388493
And set this option in various presets for buildbots.
Don't enable the checks by default because when linking against the OS library (which does not support COW checking) it will result in unresolved symbol errors.
So far it was handled by an availability checks against 9999 (which was a hack), but this does not work anymore.
Note, all this is only relevant for assert builds of the stdlib.
rdar://83673798
The type `Hasher._Core` is `@frozen` but its stored properties are `private`, which currently makes them show up in api-digester ABI reports, leading to failures like this one:
```
+Var Hasher._Core._buffer has mangled name changing from 'Swift.Hasher._Core.(_buffer in _A19879A32F7D08A6DD54BABBA00BBA0C) : Swift.Hasher._TailBuffer' to 'Swift.Hasher._Core.(_buffer in _16630011A164FCBB1F12E5E0A3A7C863) : Swift.Hasher._TailBuffer'
```
These names aren't ABI impacting, so this checker probably should ignore their name changes. (The property names do appear in the .swiftinterface files, but IIUC the only their type and ordering matters.)
These ever-changing unstable ids make it impossible to add an entry to the expectation list that would allow these tests to pass. Work around this issue by postprocessing the reports to replace the unstable parts with the constant string `#UNSTABLE ID#`.
rdar://82552099
Make both Error and CodingKey conform to ConcurrentValue, so that
thrown errors always conform to ConcurrentValue. Downgrade (to
warnings) and ConcurrentValue-related diagnostics that are triggered
by this change in existing Error and CodingKey-conforming types to
reduce the impact on source compatibility.
This is only relevant for assert builds of the library.
Fixes an undefined symbol error if an executable, compiled with an assert build of the stdlib, is back deployed on a platform which does not support lazy symbol binding.
rdar://problem/71201102
The standard library on non-Intel targets get compared to the baseline
from the Intel targets which is not guaranteed to be identical. Mark
the checks as expected failures on non-x86_64 targets. Although this is
entirely unsatisfying, it allows progress in the short term.
