Adds AllowEnhancedClassRedefinition argument.
diff --git a/src/share/vm/runtime/arguments.cpp b/src/share/vm/runtime/arguments.cpp
--- a/src/share/vm/runtime/arguments.cpp
+++ b/src/share/vm/runtime/arguments.cpp
@@ -59,8 +59,8 @@
 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
 #endif // INCLUDE_ALL_GCS
 
-// Note: This is a special bug reporting site for the JVM
-#define DEFAULT_VENDOR_URL_BUG "http://bugreport.sun.com/bugreport/crash.jsp"
+// (DCEVM) The DCE VM has its own JIRA bug tracking system.
+#define DEFAULT_VENDOR_URL_BUG "https://github.com/dcevm/dcevm/issues"
 #define DEFAULT_JAVA_LAUNCHER  "generic"
 
 // Disable options not supported in this release, with a warning if they
@@ -1507,6 +1507,10 @@
 
 void Arguments::set_ergonomics_flags() {
 
+  if (AllowEnhancedClassRedefinition) {
+    // (DCEVM) enforces serial GC
+    FLAG_SET_ERGO(bool, UseSerialGC, true);
+  }
   if (os::is_server_class_machine()) {
     // If no other collector is requested explicitly,
     // let the VM select the collector based on
@@ -1948,6 +1952,17 @@
   if (UseConcMarkSweepGC || UseParNewGC) i++;
   if (UseParallelGC || UseParallelOldGC) i++;
   if (UseG1GC)                           i++;
+
+  if (AllowEnhancedClassRedefinition) {
+    // (DCEVM) Must use serial GC. This limitation applies because the instance size changing GC modifications
+    // are only built into the mark and compact algorithm.
+    if (!UseSerialGC && i >= 1) {
+      jio_fprintf(defaultStream::error_stream(),
+                    "Must use the serial GC in the DCEVM\n");
+      status = false;
+    }
+  }
+
   if (i > 1) {
     jio_fprintf(defaultStream::error_stream(),
                 "Conflicting collector combinations in option list; "
diff --git a/src/share/vm/runtime/globals.hpp b/src/share/vm/runtime/globals.hpp
--- a/src/share/vm/runtime/globals.hpp
+++ b/src/share/vm/runtime/globals.hpp
@@ -1273,6 +1273,9 @@
   product(intx, TraceRedefineClasses, 0,                                    \
           "Trace level for JVMTI RedefineClasses")                          \
                                                                             \
+  product(bool, AllowEnhancedClassRedefinition, true,                       \
+          "Allow enhanced class redefinition beyond swapping method bodies")\
+                                                                            \
   develop(bool, StressMethodComparator, false,                              \
           "Run the MethodComparator on all loaded methods")                 \
                                                                             \