CPlusPlus: Use QVector<Token> instead of QList

Better suited to avoid the indirection (sizeof(Token) > sizeof(void *))

Change-Id: Ia5f42781e720ef6aa8161f8f81ae8ddd8e58c837
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>

src/libs/cplusplus/BackwardsScanner.h

@@ -77,7 +77,7 @@ private:
     const Token &fetchToken(int tokenIndex);
 
 private:
-    QList<Token> _tokens;
+    Tokens _tokens;
     int _offset;
     int _blocksTokenized;
     QTextBlock _block;