Add user declaration iterators in scope stack

Jumping into scope will may cause these declarations to be executed.
Therefore we need to know what the declarations are for each scope in
order acheive this.

Author: thomasspriggs

src/goto-programs/goto_convert.cpp

@@ -616,22 +616,24 @@ void goto_convertt::convert_frontend_decl(
      symbol.type.id()==ID_code)
     return; // this is a SKIP!
 
-  if(code.operands().size()==1)
-  {
-    copy(code, DECL, dest);
-  }
-  else
-  {
+  const goto_programt::targett declaration_iterator = [&]() {
+    if(code.operands().size() == 1)
+    {
+      copy(code, DECL, dest);
+      return std::prev(dest.instructions.end());
+    }
+
     exprt initializer = code.op1();
 
-    codet tmp=code;
+    codet tmp = code;
     tmp.operands().resize(1);
     // hide this declaration-without-initializer step in the goto trace
     tmp.add_source_location().set_hide();
 
     // Break up into decl and assignment.
     // Decl must be visible before initializer.
     copy(tmp, DECL, dest);
+    const auto declaration_iterator = std::prev(dest.instructions.end());
 
     auto initializer_location = initializer.find_source_location();
     clean_expr(initializer, dest, mode);
@@ -643,7 +645,9 @@ void goto_convertt::convert_frontend_decl(
 
       convert_assign(assign, dest, mode);
     }
-  }
+
+    return declaration_iterator;
+  }();
 
   // now create a 'dead' instruction -- will be added after the
   // destructor created below as unwind_destructor_stack pops off the
@@ -652,7 +656,8 @@ void goto_convertt::convert_frontend_decl(
 
   {
     code_deadt code_dead(symbol_expr);
-    targets.scope_stack.add(code_dead, {});
+
+    targets.scope_stack.add(code_dead, {declaration_iterator});
   }
 
   // do destructor