8259706: C2 compilation fails with assert(vtable_index == Method::invalid_vtable_index) failed: correct sentinel value

Reviewed-by: lucy, chagedorn

Author: TobiHartmann

src/hotspot/share/opto/library_call.cpp

@@ -3328,8 +3328,13 @@ bool LibraryCallKit::inline_unsafe_newArray(bool uninitialized) {
     // ensuing call will throw an exception, or else it
     // will cache the array klass for next time.
     PreserveJVMState pjvms(this);
-    CallJavaNode* slow_call = uninitialized ? generate_method_call_virtual(vmIntrinsics::_allocateUninitializedArray) :
-                                              generate_method_call_static(vmIntrinsics::_newArray);
+    CallJavaNode* slow_call = NULL;
+    if (uninitialized) {
+      // Generate optimized virtual call (holder class 'Unsafe' is final)
+      slow_call = generate_method_call(vmIntrinsics::_allocateUninitializedArray, false, false);
+    } else {
+      slow_call = generate_method_call_static(vmIntrinsics::_newArray);
+    }
     Node* slow_result = set_results_for_java_call(slow_call);
     // this->control() comes from set_results_for_java_call
     result_reg->set_req(_slow_path, control());