[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/PreprocessorEnvironment.h

@@ -53,6 +53,7 @@
 #define CPLUSPLUS_PP_ENVIRONMENT_H
 
 #include "CPlusPlusForwardDeclarations.h"
+#include "PPToken.h"
 
 #include <QList>
 #include <QByteArray>
@@ -78,6 +79,7 @@ public:
     Macro *remove(const QByteArray &name);
 
     Macro *resolve(const QByteArray &name) const;
+    Macro *resolve(const Internal::ByteArrayRef &name) const;
 
     iterator firstMacro() const;
     iterator lastMacro() const;
@@ -85,10 +87,11 @@ public:
     void reset();
     void addMacros(const QList<Macro> &macros);
 
-    static bool isBuiltinMacro(const QByteArray &name);
+    static bool isBuiltinMacro(const Internal::ByteArrayRef &name);
 
 private:
     static unsigned hashCode(const QByteArray &s);
+    static unsigned hashCode(const Internal::ByteArrayRef &s);
     void rehash();
 
 public: