A zippered framework is a single framework that can be loaded in both
macOS and macatalyst processes. Broadly to InstallAPI, it means the same
interface can represent two separate platforms.
A dylib's symbol table does not distinguish between macOS/macCatalyst.
`InstallAPI` provides the ability for the tbd file to distinct
symbols between them.
The verifier handles this special logic by tracking all unavailable and
obsoleted APIs in this context and checking against those when
determining dylib symbols with no matching declaration.
* If there exists an available decl for either platform, do not warn.
* If there is no available decl, emit a diagnostic and print the source
location for both decls.
* Capture reexported libraries, allowable clients, rpaths, shared cache
eligibility.
* Add support for select Xarch options.
* Add diagnostics related to capturing these options.
* Add support for verifying these attributes against what is encoded in
the dylib.
* A lot of `tapi installapi` options are already shared with clang, but
not all. This patch handles installapi-specific options by filtering for
them in the initial argv input, then passing the rest to the clang
driver.
* Installapi not only generates a text file but also reports to library
developers when there are inconsistencies between an interface and its
implementation. To allow this, add support for reporting installapi
diagnostics. This will be leveraged in the verifier service.
