added access function for squared masses to sibyll interface

Processes/Sibyll/sibyll2.3c.cc

@@ -4,6 +4,7 @@
 #include <random>
 
 int get_nwounded() { return s_chist_.nwd; }
+double get_sibyll_mass2( int& id ) { return  s_mass1_.am2[ id ]; }
 
 double s_rndm_(int&) {
   static corsika::random::RNG& rng =

Processes/Sibyll/sibyll2.3c.h

@@ -92,6 +92,7 @@ void sib_sigma_hp_(const int&, const double&, double&, double&, double&, double*
 double s_rndm_(int&);
 
   int get_nwounded();  
+  double get_sibyll_mass2(int&);
   
 // phojet random generator setup
 void pho_rndin_(int&, int&, int&, int&);