[C++] Rewrite of the preprocessor.

This rewrite fixes a couple of issues with the pre-processor. It now
supports:
- macros in macro bodies
- stringification of parameters [cpp.stringize]
- the concatenation operator [cpp.concat]
- #include MACRO_HERE
- defined() inside macro bodies used in pp-conditions.

Change-Id: Ifdb78041fb6afadf44f939a4bd66ce2832b8601f
Reviewed-by: Roberto Raggi <roberto.raggi@nokia.com>

src/libs/cplusplus/Macro.cpp

@@ -92,19 +92,11 @@ QString Macro::decoratedName() const
 QString Macro::toString() const
 {
     QString text = decoratedName();
-    text.append(QString::fromUtf8(_definition.constData(), _definition.size()));
+    text.append(QString::fromUtf8(_definitionText.constData(), _definitionText.size()));
     return text;
 }
 
 QString Macro::toStringWithLineBreaks() const
 {
-    if (_lineBreaks.isEmpty())
-        return toString();
-
-    QString text = decoratedName();
-    QString definitionWithBreaks = QString::fromUtf8(_definition.constData(), _definition.size());
-    foreach (unsigned pos, _lineBreaks)
-        definitionWithBreaks[pos] = '\n';
-    text.append(definitionWithBreaks);
-    return text;
+    return toString();
 }