When initializing a range set with a group of overlapping, identical,
or empty ranges, the initializer can exhibit poor performance due
to removing the unneeded ranges during processing. This change uses
a partitioning scheme instead, only removing the unnecessary ranges
at the end of initialization.
* Adds RangeSet/DiscontiguousSlice to the stdlib
* Remove redundant DiscontiguousSlice.Index: Comparable conformance
* Attempt to fix embedded build
* Attempt to fix macOS test failures
* Fix Constaints/members.swift failure on linux
* Add exceptions to ABI/source checker to fix macOS tests
* Fix incremental dependency test failure
* Remove inlining/unfreeze implementation for future improvements
* Simplify indices(where:) implementation
* Address review feedback
* Add test for underscored, public slice members
* Address feedback on inlining, hashing, and initializing with unordered arrays
* Fix ABI checker issues
* Remove MutableCollection extension for DiscontiguousSlice
* Make insertion return a discardable Bool
* Fix ABI checker tests
* Fix other ABI checker tests due to dropping MutableCollection subscript
