8313905: Checked_cast assert in CDS compare_by_loader

Reviewed-by: dlong, iklam

Author: coleenp

src/hotspot/share/classfile/systemDictionaryShared.cpp

@@ -597,9 +597,9 @@ class UnregisteredClassesDuplicationChecker : StackObj {
     ClassLoaderData* loader_b = b[0]->class_loader_data();
 
     if (loader_a != loader_b) {
-      return checked_cast<int>(intptr_t(loader_a) - intptr_t(loader_b));
+      return primitive_compare(loader_a, loader_b);
     } else {
-      return checked_cast<int>(intptr_t(a[0]) - intptr_t(b[0]));
+      return primitive_compare(a[0], b[0]);
     }
   }
 

src/hotspot/share/utilities/globalDefinitions.hpp

@@ -1334,6 +1334,10 @@ template<typename K> bool primitive_equals(const K& k0, const K& k1) {
   return k0 == k1;
 }
 
+template<typename K> int primitive_compare(const K& k0, const K& k1) {
+  return ((k0 < k1) ? -1 : (k0 == k1) ? 0 : 1);
+}
+
 //----------------------------------------------------------------------------------------------------
 
 // Allow use of C++ thread_local when approved - see JDK-8282469.