Issue:

java -version on zero variant slowdebug build triggers the following assertion:
     
Internal Error (hotspot/src/cpu/zero/vm/cppInterpreter_zero.cpp:829), pid=14939, tid=140070978430720
# assert(synchronized == false) failed: should be
     
Cause:
The change as introduced with JDK-8003426 removed some zero code in cppInterpreter_zero.cpp which called generate_normal_entry() in that same file with a value of synchronized == false unconditionally. However, since the new code calls generate_normal_entry() with either true or false, the assertion in this method is no longer valid.