Move construction of identifier into constructor

This makes it possible to find the code for constructing the identifier
for a `class_method_descriptor_exprt` by looking at
`class_method_descriptor_exprt` only. Where as previously it would have
been neccessary to search for all places where the contructor was used.

Author: thomasspriggs

jbmc/src/java_bytecode/java_bytecode_parser.cpp

@@ -760,11 +760,8 @@ void java_bytecode_parsert::rconstant_pool()
 
         irep_idt class_id = class_tag.get_identifier();
 
-        irep_idt identifier =
-          id2string(class_id) + "." + id2string(mangled_method_name);
-
         entry.expr = class_method_descriptor_exprt{
-          type, mangled_method_name, class_id, name_entry.s, identifier};
+          type, mangled_method_name, class_id, name_entry.s};
       }
       break;
 

jbmc/unit/java_bytecode/goto-programs/remove_virtual_functions_without_fallback.cpp

@@ -133,11 +133,8 @@ SCENARIO(
   const symbolt &callee_symbol =
     symbol_table.lookup_ref("java::VirtualFunctionsTestParent.f:()V");
 
-  class_method_descriptor_exprt callee{callee_symbol.type,
-                                       "f:()V",
-                                       "java::VirtualFunctionsTestParent",
-                                       "f",
-                                       callee_symbol.name};
+  class_method_descriptor_exprt callee{
+    callee_symbol.type, "f:()V", "java::VirtualFunctionsTestParent", "f"};
 
   const code_function_callt call(
     callee,

src/util/std_expr.h

@@ -4609,14 +4609,14 @@ class class_method_descriptor_exprt : public nullary_exprt
     typet _type,
     irep_idt mangled_method_name,
     irep_idt class_id,
-    irep_idt base_method_name,
-    irep_idt identifier)
+    irep_idt base_method_name)
     : nullary_exprt(ID_virtual_function, std::move(_type))
   {
+    irep_idt id = id2string(class_id) + "." + id2string(mangled_method_name);
     set(ID_component_name, std::move(mangled_method_name));
     set(ID_C_class, std::move(class_id));
     set(ID_C_base_name, std::move(base_method_name));
-    set(ID_identifier, std::move(identifier));
+    set(ID_identifier, std::move(id));
   }
 
   /// The method name after mangling it by combining it with the descriptor.