Instead, use the `%target-swift-5.1-abi-triple` substitution to compile the tests
for deployment to the minimum OS versions required for use of _Concurrency APIs.
From the perspective of the IR, we are changing SILIsolationInfo such that
inferring an actor instance means looking at equivalence classes of values where
we consider operands to look through instructions to be equivalent to their dest
value. The result is that cases where the IR maybe puts in a copy_value or the
like, we consider the copy_value to have the same isolation info as using the
actor directly. This prevents a class of crashes due to merge failings. Example:
```swift
actor MyActor {
init() async {
init(ns: NonSendableKlass) async {
self.k = NonSendableKlass()
self.helper(ns)
}
func helper(_ newK: NonSendableKlass) {}
}
```
Incidently, we already had a failing test case from this behavior rather than
the one that was the original genesis. Specifically:
1. If a function's SILIsolationInfo is the same as the isolation info of a
SILValue, we assume that no transfer actually occurs.
2. Since we were taking too static of a view of actor instances when comparing,
we would think that a SILIsolationInfo of a #isolation parameter to as an
argument would be different than the ambient's function isolation which is also
that same one. So we would emit a transfer non transferrable error if we pass in
any parameters of the ambient function into another isolated function. Example:
```swift
actor Test {
@TaskLocal static var local: Int?
func withTaskLocal(isolation: isolated (any Actor)? = #isolation,
_ body: (consuming NonSendableValue, isolated (any Actor)?) -> Void) async {
Self.$local.withValue(12) {
// We used to get these errors here since we thought that body's isolation
// was different than the body's isolation.
//
// warning: sending 'body' risks causing data races
// note: actor-isolated 'body' is captured by a actor-isolated closure...
body(NonSendableValue(), isolation)
}
}
}
```
rdar://129400019
As part of this I went through how we handled inference and rather than using a
grab-bag getActorIsolation that was confusing to use, I created split APIs for
specific use cases (actor instance, global actor, just an apply expr crossing)
that makes it clearer inside the SILIsolationInfo::get* APIs what we are
actually trying to model. I found a few issues as a result and fixed most of
them if they were small. I also fixed one bigger one around computed property
initializers in the next commit. There is a larger change I didn't fix around allowing function
ref/partial_apply with isolated self parameters have a delayed flow sensitive
actor isolation... this will be fixed in a subsequent commit.
This also fixes a bunch of cases where we were printing actor-isolated instead
of 'self' isolated.
rdar://127295657
