* listen_and_serv use localscope

* fix ut

* Fix a bug related to dispensable inputs and refine the inference unittest.

* Fix the use of dispensable inputs in reshape_op.

* Polish the enforce statements.

* Fix an English writing typo.

generate timeline file
PYTHONPATH=/paddle/dev/my/build2/python/ python /paddle/dev/my/Paddle2/tools/timeline.py --profile_path=train=run_inference_profiler --timeline_path=/tmp/timeline_infer
visualize it
open url chrome://tracing

* add test float16 inference accuracy example

* complete the test

* clean code

* add argument parse and refine tests

* add shell script

* add float16 benchmark code

* refine code

* prepare for contrib/float16

* put things in contrib float16 folder

* update benchmark result

* further update benchmark report

* add float16 inference report

* update report

* add float16 transpiler

* fix feed fetch target names mismatch

* fix cast op input change issue

* fix program desc flush error

* fix inconsistent var names in block desc bug

* code clean up

* add float16 infernce C++ example and fix prune bug

* Add USE_OP of all operators and kernels and remove ARCHIVE_START/END in CMakeLists.txt of inference unittests.

* Remove ARCHIVE_START/END when linking inference shared library.

* Disable some fluid related cmake operations for cross-compiling.

* Correct inference

* Update

* Update

* Add profiling information for inference example, recognize digits.

* Refine the profiling method.

* Correct the use of RecordEvent and simplify recognize_digits.