Avoid some crashes on erroneous programs.

From-SVN: r167670

gcc/go/gofrontend/expressions.cc

@@ -1146,7 +1146,11 @@ Func_expression::get_tree_without_closure(Gogo* gogo)
     }
 
   Named_object* no = this->function_;
-  tree id = this->function_->get_id(gogo);
+
+  tree id = no->get_id(gogo);
+  if (id == error_mark_node)
+    return error_mark_node;
+
   tree fndecl;
   if (no->is_function())
     fndecl = no->func_value()->get_or_make_decl(gogo, no, id);
@@ -1155,6 +1159,9 @@ Func_expression::get_tree_without_closure(Gogo* gogo)
   else
     gcc_unreachable();
 
+  if (fndecl == error_mark_node)
+    return error_mark_node;
+
   return build_fold_addr_expr_loc(this->location(), fndecl);
 }
 

gcc/go/gofrontend/types.cc

@@ -6864,6 +6864,8 @@ Named_type::do_get_tree(Gogo* gogo)
 	  t = make_node(RECORD_TYPE);
 	  this->named_tree_ = t;
 	  t = this->type_->interface_type()->fill_in_tree(gogo, t);
+	  if (t == error_mark_node)
+	    return error_mark_node;
 	}
       break;