remove the trivial constructor from symex_targett::sourcet

Author: Daniel Kroening

src/goto-symex/symex_target.h

@@ -39,14 +39,9 @@ class symex_targett
     // The program counter is an iterator which indicates where the execution
     // is in its program sequence
     goto_programt::const_targett pc;
-    bool is_set;
-
-    sourcet() : thread_nr(0), function(irep_idt()), is_set(false)
-    {
-    }
 
     sourcet(const irep_idt &_function, goto_programt::const_targett _pc)
-      : thread_nr(0), function(_function), pc(_pc), is_set(true)
+      : thread_nr(0), function(_function), pc(_pc)
     {
     }
 
@@ -55,8 +50,7 @@ class symex_targett
       const goto_programt &_goto_program)
       : thread_nr(0),
         function(_function),
-        pc(_goto_program.instructions.begin()),
-        is_set(true)
+        pc(_goto_program.instructions.begin())
     {
     }
   };