C++: Only parse with appropriate defines for open editors.

If two files from different (sub-)projects include the same header file,
and the defined macros differ for both files, the header file will be
parsed with only the appropriate macros for the including file.

Task-number: QTCREATORBUG-9802
Task-number: QTCREATORBUG-1249

Change-Id: I560490afa287b3bb1e863bce1bb4f57af36ad56e
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@digia.com>

src/libs/cplusplus/CppDocument.h

@@ -104,6 +104,10 @@ public:
     QByteArray utf8Source() const;
     void setUtf8Source(const QByteArray &utf8Source);
 
+    QByteArray fingerprint() const { return m_fingerprint; }
+    void setFingerprint(const QByteArray &fingerprint)
+    { m_fingerprint = fingerprint; }
+
     void startSkippingBlocks(unsigned offset);
     void stopSkippingBlocks(unsigned offset);
 
@@ -361,6 +365,8 @@ private:
      /// the macro name of the include guard, if there is one.
     QByteArray _includeGuardMacroName;
 
+    QByteArray m_fingerprint;
+
     QByteArray _source;
     QDateTime _lastModified;
     QAtomicInt _keepSourceAndASTCount;