Use typet instead of nil_typet when we really don't care

The type will be initialised later on, e.g., as part of type checking. (And
nil_typet is deprecated.)

Author: tautschnig

jbmc/unit/java_bytecode/load_method_by_regex.cpp

@@ -92,7 +92,7 @@ static symbolt create_method_symbol(const std::string &method_name)
 {
   symbolt new_symbol;
   new_symbol.name = method_name;
-  new_symbol.type = java_method_typet{{}, nil_typet{}};
+  new_symbol.type = java_method_typet{{}, typet{}};
   return new_symbol;
 }
 

src/goto-programs/string_abstraction.cpp

@@ -682,9 +682,8 @@ const typet &string_abstractiont::build_abstraction_type_rec(const typet &type,
   if(known_entry!=known.end())
     return known_entry->second;
 
-  ::std::pair< abstraction_types_mapt::iterator, bool > map_entry(
-      abstraction_types_map.insert(::std::make_pair(
-          eff_type, nil_typet())));
+  ::std::pair<abstraction_types_mapt::iterator, bool> map_entry(
+    abstraction_types_map.insert(::std::make_pair(eff_type, typet())));
   if(!map_entry.second)
     return map_entry.first->second;
 

src/jsil/jsil_parse_tree.cpp

@@ -70,9 +70,7 @@ void jsil_declarationt::to_symbol(symbolt &symbol) const
 
   irept throws(find(ID_throw));
   side_effect_expr_throwt t(
-    symbol_exprt::typeless(throws.get(ID_value)),
-    nil_typet(),
-    s.source_location());
+    symbol_exprt::typeless(throws.get(ID_value)), typet(), s.source_location());
   code_expressiont ct(t);
 
   if(insert_at_label(r, returns.get(ID_label), code))