Latest TFLite converter failed on fused operators
Hi @psunn ,
I have reproduced the code on tensorflow : 2.15.0. on colab with both CPU and GPU. It is working fine. Please find the [gist](https://colab.research.google.com/gist/LakshmiKalaKadali/b54aa438352215f8921dae753811de17/-62469gpu.ipynb).  


Thank You This issue is stale because it has been open for 7 days with no activity. It will be closed if no further activity occurs. Thank you. This issue was closed because it has been inactive for 7 days since being marked as stale. Please reopen if you'd like to work on this further. Are you satisfied with the resolution of your issue?
<a href="https://docs.google.com/forms/d/e/1FAIpQLSfaP12TRhd9xSxjXZjcZFNXPGk4kc1-qMdv3gc6bEP90vY1ew/viewform?entry.85265664=Yes&entry.2137816233=https://github.com/tensorflow/tensorflow/issues/62469">Yes</a>
<a href="https://docs.google.com/forms/d/e/1FAIpQLSfaP12TRhd9xSxjXZjcZFNXPGk4kc1-qMdv3gc6bEP90vY1ew/viewform?entry.85265664=No&entry.2137816233=https://github.com/tensorflow/tensorflow/issues/62469">No</a>

The latest TFLite converter seems unable to handle [fused operators ](https://www.tensorflow.org/lite/models/convert/operation_fusion#wrap_the_composite_operation_in_a_tffunction)

tflite.converter would be crashed on:
<details><summary>

code to reproduce

</summary>

```
import tensorflow as tf
print(f"TensorFlow version: {tf.version.VERSION}")

def get_implements_signature():
    implements_signature = [
        'name: "exp_sin"',
        'attr {key: "tfl_fusable_op" value { b: true } }',
    ]
    return " ".join(implements_signature)


@tf.function(experimental_implements=get_implements_signature())
def exp_sin(x):
    x = tf.math.exp(x)
    x = tf.math.sin(x)
    return x


class custom_example(tf.keras.layers.Layer):
    def call(self, inputs):
        return exp_sin(inputs)


x_in = x = tf.keras.layers.Input(shape=(10, 10, 3), batch_size=1)
x = custom_example()(x)
x = tf.keras.layers.Conv2D(filters=8, kernel_size=4)(x)
model = tf.keras.Model(inputs=x_in, outputs=x, name="example")
model.summary()

converter = tf.lite.TFLiteConverter.from_keras_model(model)
converter.optimizations = [tf.lite.Optimize.DEFAULT]
with open("model_fp32.tflite", "wb") as f:
    f.write(converter.convert())
```
</details>

<details><summary>

error log

</summary>

```
2023-11-23 18:04:30.184288: I tensorflow/core/platform/cpu_feature_guard.cc:182] This TensorFlow binary is optimized to use available CP
U instructions in performance-critical operations.                                                                                      
To enable the following instructions: AVX2 AVX512F FMA, in other operations, rebuild TensorFlow with the appropriate compiler flags.    
TensorFlow version: 2.16.0-dev20231123                                                                                                  
...
2023-11-23 18:04:32.068288: W tensorflow/compiler/mlir/lite/python/tf_tfl_flatbuffer_helpers.cc:378] Ignored output_format.
2023-11-23 18:04:32.068331: W tensorflow/compiler/mlir/lite/python/tf_tfl_flatbuffer_helpers.cc:381] Ignored drop_control_dependency.
2023-11-23 18:04:32.069026: I tensorflow/cc/saved_model/reader.cc:83] Reading SavedModel from: /tmp/tmp72ka81_f
2023-11-23 18:04:32.069483: I tensorflow/cc/saved_model/reader.cc:51] Reading meta graph with tags { serve }
2023-11-23 18:04:32.069501: I tensorflow/cc/saved_model/reader.cc:146] Reading SavedModel debug info (if present) from: /tmp/tmp72ka81_f
2023-11-23 18:04:32.074256: I tensorflow/compiler/mlir/mlir_graph_optimization_pass.cc:388] MLIR V1 optimization pass is not enabled
2023-11-23 18:04:32.074898: I tensorflow/cc/saved_model/loader.cc:233] Restoring SavedModel bundle.
2023-11-23 18:04:32.114217: I tensorflow/cc/saved_model/loader.cc:217] Running initialization op on SavedModel bundle at path: /tmp/tmp72ka81_f
2023-11-23 18:04:32.120217: I tensorflow/cc/saved_model/loader.cc:316] SavedModel load for tags { serve }; Status: success: OK. Took 51193 microseconds.
2023-11-23 18:04:32.133808: I tensorflow/compiler/mlir/tensorflow/utils/dump_mlir_util.cc:269] disabling MLIR crash reproducer, set env var `MLIR_CRASH_REPRODUCER_DIRECTORY` to enable.
loc(fused["ReadVariableOp:", callsite("example_1/conv2d_1/ReadVariableOp@__inference_serving_default_47"("/media/WORK/discovery/NGP_issues/test_models/simple_float_test.py":33:1) at callsite("/home/pensun01/anaconda3/envs/py39/lib/python3.9/site-packages/tensorflow/lite/python/lite.py":1139:1 at callsite("/home/pensun01/anaconda3/envs/py39/lib/python3.9/site-packages/tensorflow/lite/python/lite.py":1093:1 at callsite("/home/pensun01/anaconda3/envs/py39/lib/python3.9/site-packages/tensorflow/lite/python/lite.py":1601:1 at callsite("/home/p
ensun01/anaconda3/envs/py39/lib/python3.9/site-packages/tensorflow/lite/python/lite.py":1579:1 at callsite("/home/pensun01/anaconda3/env
s/py39/lib/python3.9/site-packages/tensorflow/lite/python/convert_phase.py":205:1 at callsite("/home/pensun01/anaconda3/envs/py39/lib/py
thon3.9/site-packages/tensorflow/lite/python/lite.py":1502:1 at callsite("/home/pensun01/anaconda3/envs/py39/lib/python3.9/site-packages
/keras/src/backend/tensorflow/layer.py":57:1 at callsite("/home/pensun01/anaconda3/envs/py39/lib/python3.9/site-packages/keras/src/backe
nd/tensorflow/layer.py":119:1 at callsite("/home/pensun01/anaconda3/envs/py39/lib/python3.9/site-packages/keras/src/utils/traceback_util
s.py":118:1 at callsite("/home/pensun01/anaconda3/envs/py39/lib/python3.9/site-packages/keras/src/layers/layer.py":830:1 at callsite("/h
ome/pensun01/anaconda3/envs/py39/lib/python3.9/site-packages/keras/src/utils/traceback_utils.py":118:1 at callsite("/home/pensun01/anaco
nda3/envs/py39/lib/python3.9/site-packages/keras/src/ops/operation.py":42:1 at callsite("/home/pensun01/anaconda3/envs/py39/lib/python3.
9/site-packages/keras/src/utils/traceback_utils.py":157:1 at callsite("/home/pensun01/anaconda3/envs/py39/lib/python3.9/site-packages/ke
ras/src/models/functional.py":188:1 at callsite("/home/pensun01/anaconda3/envs/py39/lib/python3.9/site-packages/keras/src/ops/function.p
y":153:1 at callsite("/home/pensun01/anaconda3/envs/py39/lib/python3.9/site-packages/keras/src/models/functional.py":572:1 at callsite("
/home/pensun01/anaconda3/envs/py39/lib/python3.9/site-packages/keras/src/utils/traceback_utils.py":118:1 at callsite("/home/pensun01/ana
conda3/envs/py39/lib/python3.9/site-packages/keras/src/layers/layer.py":830:1 at callsite("/home/pensun01/anaconda3/envs/py39/lib/python
3.9/site-packages/keras/src/utils/traceback_utils.py":118:1 at callsite("/home/pensun01/anaconda3/envs/py39/lib/python3.9/site-packages/
keras/src/ops/operation.py":42:1 at callsite("/home/pensun01/anaconda3/envs/py39/lib/python3.9/site-packages/keras/src/utils/traceback_u
tils.py":157:1 at callsite("/home/pensun01/anaconda3/envs/py39/lib/python3.9/site-packages/keras/src/layers/convolutional/base_conv.py":
227:1 at callsite("/home/pensun01/anaconda3/envs/py39/lib/python3.9/site-packages/keras/src/ops/numpy.py":4533:1 at callsite("/home/pens
un01/anaconda3/envs/py39/lib/python3.9/site-packages/keras/src/backend/tensorflow/numpy.py":1183:1 at "/home/pensun01/anaconda3/envs/py3
9/lib/python3.9/site-packages/keras/src/backend/tensorflow/core.py":65:1)))))))))))))))))))))))))]): error: missing attribute 'value'
LLVM ERROR: Failed to infer result type(s).
Aborted (core dumped)
```

</details>

This usecase is working on earlier versions, i.g., TensorFlow version: 2.14.1
But it would be failed on recent versions, i.g., TensorFlow version: 2.15.0 ~ TensorFlow version: 2.16.0-dev20231123
