The driver now holds a reference to the 'swiftScanLibInstance' which is shared with the 'interModuleDependencyOracle', but is also used for target info and supported compiler feature queries. This means a single SwiftScan instance is shared across all uses in a given driver instance.
Allow SwiftScan to be instantiated without a path to an external 'libSwiftScan.dylib', which will cause it to 'dlopen' with a NULL argument, and expect the scanner symbols to be found in the image that the driver code is a part of. This is useful for when compiler-based tooling (SourceKit) links the driver directly and uses its C API.
Added a deprecation for the prior version of verifyOrCreateScannerInstance.
Added a deprecation for the prior version of
verifyOrCreateScannerInstance
.