Apply suggestions from MSVC workaround

Author: compnerd

lib/Parse/ParseDecl.cpp

@@ -9381,9 +9381,8 @@ Parser::parseDeclPrecedenceGroup(ParseDeclOptions flags,
   auto checkCodeCompletion =
       [&](CodeCompletionCallbacks::PrecedenceGroupCompletionKind SK) -> bool {
     if (Tok.is(tok::code_complete)) {
-      if (CodeCompletionCallbacks) {
-        CodeCompletionCallbacks->completeInPrecedenceGroup(SK);
-      }
+      if (this->CodeCompletionCallbacks)
+        this->CodeCompletionCallbacks->completeInPrecedenceGroup(SK);
       consumeToken();
       return true;
     }

lib/Parse/ParseExpr.cpp

@@ -734,9 +734,8 @@ ParserResult<Expr> Parser::parseExprKeyPathObjC() {
           Context, keywordLoc, lParenLoc, components, Tok.getLoc());
     }
 
-    if (CodeCompletionCallbacks) {
-      CodeCompletionCallbacks->completeExprKeyPath(expr, DotLoc);
-    }
+    if (this->CodeCompletionCallbacks)
+      this->CodeCompletionCallbacks->completeExprKeyPath(expr, DotLoc);
 
     // Eat the code completion token because we handled it.
     consumeToken(tok::code_complete);

lib/Parse/ParsePattern.cpp

@@ -245,9 +245,8 @@ Parser::parseParameterClause(SourceLoc &leftParenLoc,
     if (paramContext != ParameterContextKind::EnumElement) {
       auto AttrStatus = parseDeclAttributeList(param.Attrs);
       if (AttrStatus.hasCodeCompletion()) {
-        if (CodeCompletionCallbacks) {
-          CodeCompletionCallbacks->setAttrTargetDeclKind(DeclKind::Param);
-        }
+        if (this->CodeCompletionCallbacks)
+          this->CodeCompletionCallbacks->setAttrTargetDeclKind(DeclKind::Param);
         status.setHasCodeCompletionAndIsError();
       }
     }