Qml scanner: Fix begin location of comment tokens in multiline comments.

Done-with: Thomas Hartmann
Reviewed-by: Roberto Raggi

src/libs/qmljs/qmljsscanner.cpp

@@ -130,9 +130,13 @@ QList<Token> Scanner::operator()(const QString &text, int startState)
     int index = 0;
 
     if (_state == MultiLineComment) {
-        const int start = index;
+        int start = -1;
         while (index < text.length()) {
             const QChar ch = text.at(index);
+
+            if (start == -1 && !ch.isSpace())
+                start = index;
+
             QChar la;
             if (index + 1 < text.length())
                 la = text.at(index + 1);