Merge pull request #4158 from JohnDumbell/jd/refactor/duplicate_field

Same field in both goto_statet and goto_symex_statet

Author: tautschnig

src/goto-symex/goto_symex_state.h

@@ -141,7 +141,6 @@ class goto_symex_statet final : public goto_statet
   /// for error traces even after symbolic execution has finished.
   symbol_tablet symbol_table;
 
-  symex_targett::sourcet source;
   symex_target_equationt *symex_target;
 
   // we remember all L1 renamings