8345237: 32-bit Zero builds fail with assert(has_klass_gap()) failed: precondition

Reviewed-by: mli, jwaters, rkennke

Author: shipilev

src/hotspot/share/interpreter/zero/bytecodeInterpreter.cpp

@@ -2013,7 +2013,9 @@ void BytecodeInterpreter::run(interpreterState istate) {
                 oopDesc::release_set_mark(result, ik->prototype_header());
               } else {
                 oopDesc::set_mark(result, markWord::prototype());
-                oopDesc::set_klass_gap(result, 0);
+                if (oopDesc::has_klass_gap()) {
+                  oopDesc::set_klass_gap(result, 0);
+                }
                 oopDesc::release_set_klass(result, ik);
               }
               oop obj = cast_to_oop(result);