As the _MatchingEngine module no longer contains the matching engine, this patch renames this module to describe its role more accurately. Because this module primarily contains the AST and the regex parsing logic, I propose we rename it to "_RegexParser".
Also renames the ExperimentalRegex module in SwiftCompilerSources to _RegexParser for consistency. This would prevent errors if sources in _RegexParser used qualified lookup with the module name.
Store a list of argument effects in a function, which specify if and how arguments escape.
Such effects can be specified in the Swift source code (for details see docs/ReferenceGuides/UnderscoredAttributes.md) or derived in an optimization pass.
For details see the documentation in SwiftCompilerSources/Sources/SIL/Effects.swift.
The `run-unit-tests` is a "pseudo" pass which is invoked from sil-opt and runs all the unit tests, implemented in Swift.
This is done from the `swift-unit-tests.sil` lit test.
* add `BasicBlockSet`
* add `BasicBlockWorklist`
* add `BasicBlockRange`, which defines a range of blocks from a common dominating “begin” block to a set of “end” blocks.
* add `InstructionRange`, which is similar to `BasicBlockRange`, just on instruction level. It can be used for value lifetime analysis.
* rename `StackList` -> `Stack` and move it to `Optimizer/DataStructures`
* rename `PassContext.passContext` to `PassContext._bridged`
* add notify-functions to PassContext
