* Enable INT8 ReQuantize OP
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* Clean code
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* Add comments
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* Revert "Clean code"
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This reverts commit a7a49b8aa214f9730cb84e11ea96da564fe4b4d9.

* Modify requantize op test
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* fix requantize UT by moving public function to public test file.
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* Fix test fail due to file address change.
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* Change file address for requantize op.
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test=develop