Changes to make isolate reload functionality work with the --dfe option.

runtime/bin/run_vm_tests.cc

Index: runtime/bin/run_vm_tests.cc
diff --git a/runtime/bin/run_vm_tests.cc b/runtime/bin/run_vm_tests.cc
index 103fede8f86396548ea326c36eeb45e9000d7873..a2472dce56f28169503579da537b67c0b3977fac 100644
--- a/runtime/bin/run_vm_tests.cc
+++ b/runtime/bin/run_vm_tests.cc
@@ -5,6 +5,7 @@
 #include <stdio.h>
 
 #include "bin/dartutils.h"
+#include "bin/dfe.h"
 #include "bin/file.h"
 #include "bin/loader.h"
 #include "bin/platform.h"
@@ -24,6 +25,10 @@ extern const uint8_t kDartCoreIsolateSnapshotInstructions[];
 // TODO(iposva, asiva): This is a placeholder for the real unittest framework.
 namespace dart {
 
+namespace bin {
+DFE dfe;
+}
+
 // Defined in vm/os_thread_win.cc
 extern bool private_flag_windows_run_tls_destructors;