This also removes `BridgedDiagnosticArgumentKind` in favor of `swift::DiagnosticArgumentKind`, bringing us one step closer to bridging the entire diagnostic engine via C++ interop.
rdar://83361087
C++ interop is now enabled in SwiftCompilerSources, so we can remove some of the C bridging layer and use C++ classes directly from Swift.
rdar://83361087
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
