Before this change in the following code, we would say that message is isolated to the actor instead of the global actor isolation of the actor's method:
```swift
class Message { ... }
actor MessageHolder {
@MainActor func hold(_ message: Message) { ... }
}
@MainActor
func sendMessage() async {
let messageHolder = MessageHolder()
let message = Message()
// We identified messageHolder.hold as being MessageHolder isolated
// instead of main actor isolated.
messageHolder.hold(message)
Task { @MainActor in print(message) }
}
```
I also used this as an opportunity to simplify the logic in this part of the
code. Specifically, I had made it so that multiple interesting cases were
handled in the same conditional statement in a manner that it made it hard to
know which cases were actually being handled and why it was correct. Now I split
that into two separate if statements with comments that make it clear what we
are actually trying to pattern match against.
rdar://130980933
Replace the assert-check if a vtable is available with a regular error message.
This cannot occur in regular builds - only if built with embedded swift and without wmo.
The command line compiler prevents this combination, but it can happen in SourceKit.
rdar://130167087
Specifically:
1. We error now if one transfers an 'inout sending' parameter and does not
reinitialize it before the end of the function.
2. We error now if one merges an 'inout sending' parameter into an actor
isolated region and do not reinitialize it with a non-actor isolated value
before the end of the function.
rdar://126303739
The reason why I am doing this is that I am adding support for failing to
reinitialize an inout sending parameter that was transferred. To make it really
easy to do I am just going to explicitly represent this on the RequireInst and
let the decision on what diagnostic to be done to be represented in the
pseudo-IR instead of trying to just infer it straight from the type of require
inst. This keeps all of the logic in the same place and attempts to keep the
diagnostic emitter not use logic and instead just emit.
This is NFC so I can make sure that things work before adding the additional code.
Remove `deque` from files it isn't actually used in. Add it and `stack`
to files that it is - presumably they were previously transitively found
through other includes.
This was causing us to emit old style diagnostics in certain cases.
Just doing a walk through of the diagnostics and fixing issues while I
am here sprucing up sending diagnostics.
rdar://130915737
This asserts only option is an option to make it quicker/easier to triage
unknown pattern match errors by aborting when we emit it (allowing one to
immediately drop into the debugger at that point).
Previously, it only happened for errors in RegionAnalysis not in
TransferNonSendable itself.
