[Parser] Make PersistentParserState parameter optional and remove it from the constructor that accepts a StringRef fragment.

Swift SVN r6592

Author: akyrtzi

include/swift/Parse/Parser.h

@@ -132,9 +132,9 @@ class Parser {
 public:
   Parser(unsigned BufferID, TranslationUnit *TU,
          bool IsMainModule, SILParserState *SIL,
-         PersistentParserState *PersistentState);
+         PersistentParserState *PersistentState = nullptr);
   Parser(TranslationUnit *TU, llvm::StringRef fragment, DiagnosticEngine &Diags,
-         SILParserState *SIL, PersistentParserState *PersistentState = nullptr);
+         SILParserState *SIL);
   ~Parser();
 
   bool isInSILMode() const { return SIL != nullptr; }

lib/Parse/Parser.cpp

@@ -239,9 +239,9 @@ Parser::Parser(unsigned BufferID, TranslationUnit *TU,
 
 Parser::Parser(TranslationUnit *TU,
                llvm::StringRef fragment, DiagnosticEngine &Diags,
-               SILParserState *SIL, PersistentParserState *PersistentState)
+               SILParserState *SIL)
   : Parser(new Lexer(fragment, SourceMgr, &Diags, SIL != nullptr),
-           TU, Diags, SIL, PersistentState) {
+           TU, Diags, SIL, /*PersistentState=*/nullptr) {
 }
 
 Parser::~Parser() {