* add flatbuffers, test=develop

* fix cmake codes, test=develop

* [LITE][PASS] Add pass for removing uesless reshape2 / squeeze2. test=develop

* [LITE][OPENCL] Fix grid sampler for mali gpu. test=develop

* reduce .so size. test=develop

* compile all targets when LITE_ON_TINY_PUBLISH=OFF

* unordered_map is more convenient when key is customized class

* test=develop

* test=develop,test=coverage, support coverage CI on x86 server

* test=develop,test=coverage, fix the conflict

* test=develop,test=coverage, add target code_coverage

* test=develop,test=coverage, modify the coveralls.cmake

* Add places of int64 and any precision in opt, test=develop

[LITE][XPU] 1. Add precision switch(int16/int31) in XPUMultiEncoderOp; 2. Fix identity_dropout_eliminate_pass, |AttrType| of 'is_test' in OpDesc can be INT or BOOLEAN; 3. Enhance |__xpu__multi_encoder_fuse_pass|; (#3596)

* [LITE][XPU] Add precision switch(int16/int31) in XPUMultiEncoderOp

* [LITE][XPU] fix identity_dropout_eliminate_pass, |AttrType| of 'is_test' in OpDesc can be INT or BOOLEAN

* test=develop

* [LITE][XPU] suppress linkage error
test=develop

* [LITE][XPU] 1. Reorder |identity_dropout_eliminate_pass| before |__xpu__multi_encoder_fuse_pass|; 2. Enhance |__xpu__multi_encoder_fuse_pass|, it works well in more scenarios;
test=develop

* [LITE][XPU] Remove XPUConfig
test=develop

* test=develop, support WITH_TESTING=ON on windows

test=develop, modify the path of test_file in build_windows.bat

test=develop, modify the docment of windows compilation

test=develop, modify the document

* test=develop, modify the build_windows.bat

* add eltwise_activate_fuse. test=develop

* [LITE][BM] fix reshape infer shape issue, optimize global pool,adaptive pool,multi thread 

* support opencl for multi-thread test. test=develop

* add scale+relu/relu6/leakyrelu test=develop
* fix format， test=develop

* fix cuda demo. test=develop

* update type error. test=develop

* Fix Places of CXX Config for OpenCL. test=develop

* fix shared ptr as unqiue ptr. test=develop

refactor(*): reduce Wsign-compare warning