Add name to dummy expression

also use pointer-type builder instead of constructor.

Author: petr-bauch

src/memory-analyzer/analyze_symbol.cpp

@@ -151,7 +151,7 @@ exprt gdb_value_extractort::get_char_pointer_value(
     string_constantt init(string);
     CHECK_RETURN(to_array_type(init.type()).is_complete());
 
-    symbol_exprt dummy(pointer_typet(init.type(), config.ansi_c.pointer_width));
+    symbol_exprt dummy("tmp", pointer_type(init.type()));
     code_blockt assignments;
 
     const symbol_exprt new_symbol =