Get rid of the boolean arguments for unavailability in AvailabilityQuery's
constructors and introduce a `asUnavailable()` modifier that can be used
instead in the contexts where unavailability is relevant.
Inverted availability queries were mis-compiled for zippered libraries because
the code that emits calls to `isOSVersionAtLeastOrVariantVersionAtLeast()` was
not updated when the `if #unavailable` syntax was introduced (at that time
support for zippered libraries had not yet been upstreamed). The result of
these calls is now inverted when appropriate.
To make it easier to manage the growing complexity of supporting availability
queries, Sema now models the relevant information about an availability query
with the new `AvailabilityQuery` type. It encapsulates the domain for the
query, the result if it is known at compile time, and the version tuple
arguments to pass to a runtime invocation if applicable.
Resolves rdar://147929876.
When compiling for visionOS, iOS availability attributes are remapped into the
visionOS availability domain automatically. While the version remapping was
being performed correctly, there was a regression that caused the platform name
to be printed incorrectly in many diagnostics. Whenever an iOS version is
remapped to a visionOS version, availability diagnostics will now present
those versions as visionOS versions instead of iOS versions.
Resolves rdar://146293165.
This feature is essentially self-migrating, but fit it into the
migration flow by marking it as migratable, adding
`-strict-memory-safety:migrate`, and introducing a test.
There's a synthesized call to unsafeBitCast(_:to:), which is obvious
unsafe, and is being diagnosed as such. The compiler generates this
call, so have the compiler also generate the `unsafe` around it to
suppress these warnings.
Fixes rdar://151199011.
