Update Hybridize to use kwargs as backend opts

Signed-off-by: Serge Panev <spanev@nvidia.com>

python/mxnet/gluon/block.py

@@ -1099,7 +1099,7 @@ def optimize_for(self, x, *args, backend=None, clear=True, static_alloc=False, s
         """
 
         # do hybrize API call
-        self.hybridize(True, backend, kwargs, clear, static_alloc=static_alloc, static_shape=static_shape)
+        self.hybridize(True, backend, clear, static_alloc=static_alloc, static_shape=static_shape, **kwargs)
 
         # do part of forward API call
         has_symbol, has_ndarray, ctx_set, _ = _gather_type_ctx_info([x] + list(args))
@@ -1137,7 +1137,8 @@ def register_child(self, block, name=None):
         super(HybridBlock, self).register_child(block, name)
         self._clear_cached_op()
 
-    def hybridize(self, active=True, backend=None, backend_opts=None, clear=True, **kwargs):
+    def hybridize(self, active=True, backend=None, clear=True,
+                  static_alloc=False, static_shape=False, **kwargs):
         """Activates or deactivates :py:class:`HybridBlock` s recursively. Has no effect on
         non-hybrid children.
 
@@ -1156,23 +1157,25 @@ def hybridize(self, active=True, backend=None, backend_opts=None, clear=True, **
             Optimize for invariant input shapes between iterations. Must also
             set static_alloc to True. Change of input shapes is still allowed
             but slower.
+        **kwargs : dict
+            Optional backend options when hybridized is called with an optimization backend.
         """
 
         self._backend = backend
         if backend_opts is not None:
             assert isinstance(backend_opts, dict), \
             "HybridBlock hybridize requires backend_opts to be a dictionary."
-            self._backend_opts = backend_opts
+            self._backend_opts = kwargs
 
         self._active = active
-        self._flags = list(kwargs.items())
+        self._flags = [("static_alloc", static_alloc), ("static_shape", static_shape)]
         if clear:
             self._clear_cached_op()
         if active and self._forward_hooks or self._forward_pre_hooks:
             warnings.warn('"{block}" is being hybridized while still having forward hook/pre-hook. '
                           'If "{block}" is a child of HybridBlock, the hooks will not take effect.'
                           .format(block=self))
-        super(HybridBlock, self).hybridize(active, **kwargs)
+        super(HybridBlock, self).hybridize(active, static_alloc=static_alloc, static_shape=static_shape)
 
     def cast(self, dtype):
         self._clear_cached_op()