This fixes a dangling pointer issue when creating a `Swift.String` from `std::string`.
Also fixes a warning:
```
warning: variable 's' was never mutated; consider changing to 'let' constant
var s = SILBasicBlock_debugDescription(bridged)
~~~ ^
let
```
rdar://92963081
rdar://93053488
and introduce the StringRef struct.
It's more efficient.
Also, rename the `HasName` protocol to `HasShortDescription`, which introduces the new requirement `shortDescription`. This is need because `name` now has `StringRef` type and not `String` anymore
This fixes:
* An issue where the diagnostic messages were leaked
* Diagnose at correct position inside the regex literal
To do this:
* Introduce 'Parse' SwiftCompiler module that is a bridging layer
between '_CompilerRegexParser' and C++ libParse
* Move libswiftParseRegexLiteral and libswiftLexRegexLiteral to 'Parse'
Also this change makes 'SwiftCompilerSources/Package.swift' be configured
by CMake so it can actually be built with 'swift-build'.
rdar://92187284
