No runtime function calls will be tracked in this case, but the APIs for reading them are still available. This way there is no need to recompile Swift clients if they are linked against different builds of the standard library and runtime library.
* Mutations of slices of data should preserve relative indexing as well as cow semantics of slices
* Ensure hashes of ranges are uniform to the expected hash for Data
* Correct a few mistakes in the slice mutation tests
* Update sequence initializations to avoid directly calling mutableCopy which prevents slice offset mismatches
* Avoid invalid index slices in creating mirrors
* Restore the original Data description
* Resetting a slice region should expand the slice to the maximum of the region (not a out of bounds index of the backing buffer)
* Remove stray comment and use a stack buffer for sequence appending
* Return false when allocations fail in _resizeConditionalAllocationBuffer (not yet in use)
* Enumeration of regions of a slice should be limited to the slice range in the case of custom backing (e.g. dispatch_data_t)
* adjust assertion warnings for data indexes that are negative
JSONEncoder and PropertyListEncoder both use NSNumber to box Bool values. An encoded Bool can be coerced to any numerical type during decoding because (false as NSNumber).intValue == 0. As a remedy, all of the unbox(_:as:) methods of _JSONDecoder and _PlistDecoder for numerical types include a check that the value is not identical to either kCFBooleanTrue or kCFBooleanFalse, and throw a DecodingError._typeMismatch(at:expectation:) if this check fails.
* Unify the capitalization across all user-visible error messages (fatal errors, assertion failures, precondition failures) produced by the runtime, standard library and the compiler.
* Update some more tests to the new expectations.
At the top level, JSONEncoder/PropertyListEncoder (and the decoders) directly encoded values into an encoder instead of following the logic to box the values (and thus dispatch based on the type, potentially intercepting representations or applying strategies). This led to top-level values having a different representation than similar values throughout a payload.
CharacterView is now entirely redundant in Swift 4. Deprecate its
use. This also allows us to schedule the unbreaking of
String.CharacterView leakiness without a hard source break.
Collection's popFirst is only present when the Collection is its own
SubSequence type. String and String's views are no longer their own
SubSequenes, so popFirst is no longer present. Unfortunately, this
breaks code in swift-version 3 and it also gives a terrible diagnostic
to users. This change introduces an implementation for swift-version 3
mode and better diagnostics for Swift 4 code. Tests included.
