swift

a9dc4ed6 - [region-isolation] Refactor out the Region analysis from TransferNonSendable.

[region-isolation] Refactor out the Region analysis from TransferNonSendable. NFCI. This is just a pure refactor of the analysis part of TransferNonSendable into a separate SIL level analysis so it can be reused by other passes. The reason that I am committing this earlier is that I am working concurrently on other patches that change TransferNonSendable itself and I want to avoid issues when rebasing those patches. Getting this patch into tree earlier avoids that. This is in preparation for adding a new flow sensitive initialization pass that combines region based analysis with the current flow sensitive isolation's diagnostic emitter. The idea is that we want to preserve the diagnostics from that pass rather than try to make our own as an initial step.