Check for class id overflow to exit rather than crash.

runtime/vm/class_table.cc

Index: runtime/vm/class_table.cc
===================================================================
--- runtime/vm/class_table.cc	(revision 35144)
+++ runtime/vm/class_table.cc	(working copy)
@@ -89,6 +89,10 @@
       class_heap_stats_table_ = new_stats_table;
     }
     ASSERT(top_ < capacity_);
+    if (!Class::is_valid_id(top_)) {
+      FATAL1("Fatal error in ClassTable::Register: invalid index %" Pd "\n",

[Ivan Posva, 2014/04/18 16:39:27]

FATAL is OK for now, but we really should just throw an error in this isolate.
There is no reason to kill the process in general.

+             top_);
+    }
     cls.set_id(top_);
     table_[top_] = cls.raw();
     top_++;  // Increment next index.
@@ -102,7 +106,7 @@
   if (index >= capacity_) {
     // Grow the capacity of the class table.
     intptr_t new_capacity = index + capacity_increment_;
-    if (new_capacity < capacity_) {
+    if (!Class::is_valid_id(index) || new_capacity < capacity_) {
       FATAL1("Fatal error in ClassTable::Register: invalid index %" Pd "\n",
              index);
     }