[JIT] expose polymorphic deoptimize reason

Summary: provide Deoptimization::Reason_polymorphic in vmStructs, this
is to fix test TestPrintMdo.java and ClhsdbCDSCore.java

Testing: jtreg and ci

Reviewers: maoliang, yy

Issue: #936

src/hotspot/share/runtime/vmStructs.cpp

@@ -2445,6 +2445,7 @@ typedef PaddedEnd<ObjectMonitor>              PaddedObjectMonitor;
   declare_constant(Deoptimization::Reason_array_check)                    \
   declare_constant(Deoptimization::Reason_intrinsic)                      \
   declare_constant(Deoptimization::Reason_bimorphic)                      \
+  declare_constant(Deoptimization::Reason_polymorphic)                    \
   declare_constant(Deoptimization::Reason_profile_predicate)              \
   declare_constant(Deoptimization::Reason_unloaded)                       \
   declare_constant(Deoptimization::Reason_uninitialized)                  \