diff -r fe4349d27282 -r a65d8a6fa424 src/hotspot/share/runtime/arguments.cpp
--- a/src/hotspot/share/runtime/arguments.cpp	Thu Sep 06 16:15:32 2018 -0700
+++ b/src/hotspot/share/runtime/arguments.cpp	Thu Sep 06 18:06:24 2018 -0700
@@ -574,6 +574,7 @@
   { "PrintSafepointStatisticsCount", JDK_Version::jdk(11),     JDK_Version::jdk(12), JDK_Version::jdk(13) },
   { "TransmitErrorReport",           JDK_Version::undefined(), JDK_Version::jdk(12), JDK_Version::jdk(13) },
   { "ErrorReportServer",             JDK_Version::undefined(), JDK_Version::jdk(12), JDK_Version::jdk(13) },
+  { "EmitSync",                      JDK_Version::undefined(), JDK_Version::jdk(12), JDK_Version::jdk(13) },
 
 #ifdef TEST_VERIFY_SPECIAL_JVM_FLAGS
   { "dep > obs",                    JDK_Version::jdk(9), JDK_Version::jdk(8), JDK_Version::undefined() },
@@ -3977,7 +3978,7 @@
     }
   }
 #ifdef COMPILER2
-  if (!UseBiasedLocking || EmitSync != 0) {
+  if (!UseBiasedLocking) {
     UseOptoBiasInlining = false;
   }
 #endif