[Runtime][RPC] Fix FreeObject in minrpc server

As a followup PR to #16635, this PR fixes the FreeObject in minrpc server.

Author: Siyuan Feng

src/runtime/crt/common/crt_runtime_api.c

@@ -139,6 +139,8 @@ int TVMStreamCreate(int device_type, int device_id, TVMStreamHandle* out) {
   return 0;
 }
 
+int TVMObjectFree(TVMObjectHandle obj) { return 0; }
+
 int TVMStreamFree(int device_type, int device_id, TVMStreamHandle stream) { return 0; }
 
 int TVMSetStream(int device_type, int device_id, TVMStreamHandle stream) { return 0; }

src/runtime/minrpc/minrpc_server.h

@@ -344,6 +344,8 @@ class MinRPCExecute : public MinRPCExecInterface {
       call_ecode = TVMArrayFree(static_cast<TVMArrayHandle>(handle));
     } else if (type_code == kTVMPackedFuncHandle) {
       call_ecode = TVMFuncFree(handle);
+    } else if (type_code == kTVMObjectHandle) {
+      call_ecode = TVMObjectFree(handle);
     } else {
       MINRPC_CHECK(type_code == kTVMModuleHandle);
       call_ecode = TVMModFree(handle);

tests/python/runtime/test_runtime_rpc.py

@@ -447,6 +447,10 @@ def check(client, is_local):
         assert get_elem(shape, 0) == 2
         assert get_elem(shape, 1) == 3
         assert get_size(shape) == 2
+        # Test free object by assigning to the same variable
+        shape = make_shape(0)
+        assert get_size(shape) == 1
+        assert get_elem(shape, 0) == 0
 
     # start server