Fix getting a fresh variable for memory harness tmps

Do not introduce symbols for types and do not disregard local temporaries.

Author: Petr Bauch

src/goto-harness/memory_snapshot_harness_generator.cpp

@@ -228,22 +228,29 @@ code_blockt memory_snapshot_harness_generatort::add_assignments_to_globals(
   for(const auto &pair : snapshot)
   {
     const symbolt &snapshot_symbol = pair.second;
-    if(!snapshot_symbol.is_static_lifetime)
-      continue;
-
     symbol_tablet &symbol_table = goto_model.symbol_table;
-    const symbolt &symbol =
-      (symbol_table.lookup(snapshot_symbol.base_name) != nullptr)
-        ? snapshot_symbol
-        : fresh_symbol_copy(snapshot_symbol, symbol_table);
 
-    if(variables_to_havoc.count(symbol.base_name) == 0)
+    auto should_get_fresh = [&symbol_table](const symbolt &symbol) {
+      return symbol_table.lookup(symbol.base_name) == nullptr &&
+             !symbol.is_type;
+    };
+    const symbolt &fresh_or_snapshot_symbol =
+      should_get_fresh(snapshot_symbol)
+        ? fresh_symbol_copy(snapshot_symbol, symbol_table)
+        : snapshot_symbol;
+
+    if(!fresh_or_snapshot_symbol.is_static_lifetime)
+      continue;
+
+    if(variables_to_havoc.count(fresh_or_snapshot_symbol.base_name) == 0)
     {
-      code.add(code_assignt{symbol.symbol_expr(), symbol.value});
+      code.add(code_assignt{fresh_or_snapshot_symbol.symbol_expr(),
+                            fresh_or_snapshot_symbol.value});
     }
     else
     {
-      recursive_initialization.initialize(symbol.symbol_expr(), 0, {}, code);
+      recursive_initialization.initialize(
+        fresh_or_snapshot_symbol.symbol_expr(), 0, {}, code);
     }
   }
   return code;