* Add swift_evolve feature and disable several tests
This change adds a swift_evolve feature to our lit configuration and uses it to mark several tests as unsupported by swift_evolve.
One of these—test/api-digester/stability-stdlib-abi.swift—is actually pretty bad; we would really like to have it. But the digester has known issues exposed by swift-evolve.
* Remove order dependency in another test
* Tweaks from Jordan’s review
* Distinguish between tests which are intentionally unsupported and temporarily disabled.
* Add an explanation for one unsupproted test.
* Code nitpick.
The tool should diagnose the change of extension's applicability since
such change can be source-breaking. We need first to support the
requirements in the module dump. Currently, we decorate each
member defined in extension with a field called extension info. The
field will keep track of the generic requirements that need to be satisfied
for this decorated member to be applicable. This patch doesn't implement the checking
of requirements change.
This has three principal advantages:
- It gives some additional type-safety when working
with known accessors.
- It makes it significantly easier to test whether a declaration
is an accessor and encourages the use of a common idiom.
- It saves a small amount of memory in both FuncDecl and its
serialized form.
