analyzer: prevent ICEs with null types

Fixes some ICEs seen analyzing the Linux kernel.

gcc/analyzer/ChangeLog:
	* region-model-manager.cc (maybe_undo_optimize_bit_field_compare):
	Guard against null types.
	* region-model.cc (apply_constraints_for_gswitch): Likewise.

Signed-off-by: David Malcolm <[email protected]>

Author: davidmalcolm

gcc/analyzer/region-model-manager.cc

@@ -616,6 +616,8 @@ maybe_undo_optimize_bit_field_compare (tree type,
 				       tree cst,
 				       const svalue *arg1)
 {
+  if (!type)
+    return nullptr;
   if (!INTEGRAL_TYPE_P (type))
     return NULL;
 

gcc/analyzer/region-model.cc

@@ -5781,7 +5781,8 @@ apply_constraints_for_gswitch (const switch_cfg_superedge &edge,
 	  && is_a <const initial_svalue *> (unaryop->get_arg ()))
 	if (const initial_svalue *initvalop = (as_a <const initial_svalue *>
 					       (unaryop->get_arg ())))
-	  if (TREE_CODE (initvalop->get_type ()) == ENUMERAL_TYPE)
+	  if (initvalop->get_type ()
+	      && TREE_CODE (initvalop->get_type ()) == ENUMERAL_TYPE)
 	    {
 	      index_sval = initvalop;
 	      check_index_type = false;