[Parse] Optimize syntax parsing: Speed-up Lexer::lexTrivia()

Introduce ParsedTrivia which is a more efficient structure to use during lexing than syntax::Trivia.

tools/SourceKit/lib/SwiftLang/SwiftEditor.cpp

@@ -685,7 +685,7 @@ public:
     if (CompInv.getLangOptions().BuildSyntaxTree) {
       RC<SyntaxArena> syntaxArena{new syntax::SyntaxArena()};
       SynTreeCreator = std::make_shared<SyntaxTreeCreator>(
-          CompInv.getMainFileSyntaxParsingCache(), syntaxArena);
+          SM, BufferID, CompInv.getMainFileSyntaxParsingCache(), syntaxArena);
     }
 
     Parser.reset(