* copy boost optional.hpp to paddle

* copy boost optional.hpp to paddle

* move directions

* del fluid/utils

* modify .hpp to .h

* move directions

* modify to paddle::optional

* add modification description

* format code stype for the files in paddle/utils

* format code stype

* Remove force_fp32_output from elementwise_add quantization

* Fix cpu_quantize_placement test

* Review related changes

* scale_matmul_fuse_pass_init

* enhance scale_matmul_fuse_pass

* change scale_matmul_fuse_pass unittest

test=develop.

* - fix to #33282

* - Increased threshold for elementwise_mul_bf16 grad

* -disabled faulty UT

* - fix to approval

* batch_norm_act_fuse_pass_init

* repair the unittest of batch_norm_act

* Small changes related to BF16 fusion_gru and fusion_lstm

* Correct to pass arg by value

* Add conditions to rnn op

* Correct the spelling mistake

* Improving the test with checking activation

* Trigger CI

* Unification of bfloat16 enablement process and refactor

* Remove unnecessary function

* Standardize the output name search

* Add conv transpose BF16

* Share function GetWeightsTz

* Adjust to review and fix op compatibility

* Add bias to unique handler name

* Remove errors related to paddle enforce

* Add conv2d_transpose to bf16 list and kernel refator

* Move pass tester helper functions to single common place.

* Use helper functions in two more fuse pass tests.

* skip quantizing ops in cpu inference, test=develop

* Add mkldnn nearest_interp and bilinear_interp op
* don't run mkldnn interpolate in default
* add interpolate_mkldnn_pass

* add the support the op version check for matmul, test=op_version

* add the op version check for the elementwise ops, test=op_version

* add the support check for elementwise_ops, test=op_version

* map matmul/squeeze2+matmul/reshape2+matmul to mul

* Add bf16 pool2d and unify bf16 unit tests

* Add change default ops test

* Fix cpu_bfloat16_pass

* Add output_format

* Fix incorrect SetOutput

* Change fromating

* Add multi_gru_fuse_pass and tests

* fix date

* cleaned up headers

* Add multi_gru_seq_fuse_pass and tests

* fix date

* removed unused functions

* Add bf16 matmul, fc, elementwise add and mul

* Correct unit test

* Add checkpoint to quantize

* Change bfloat16 option