cross compile x86 linux (#562)

* cross compile x86 linux

* fix comments

* install multilib for ubuntu cross compile

* remove tailing slash

* fix -fPIC relocations for x86 target too

* add asm make flag

* fix x86 compile err

* test x86 with zlib and png

* Disable zlib from x86

* install x86 python header

* remove cross-compiling changes

* test 32bit ubuntu

* add x86 ubuntu docker file

* add x86 as arch parametr for docker build

* config pipeline

* avoid dotnet install

* install cmake

* skip dep install

* use latest ubuntu

* install latest cmake

* install x86 deps

* configure cmake

* install ninja

* correct ninja dir

* apt get re2c

* install onnx

* set processor x86

* disable warning

* skip test

* disable test

* disable test

* find lib

* fix typo

* restore test

* disable backend model test

* disable test

* fix test err

* stop installing onnx

* disable onnx test on x86

* restore yml

* mergef with master yml

* cancel needless config setting

* enable x86 flag

* restore all onnx tests

* fix yml typo

* install onnx

* add back x86 flag

* disable cases

* disable case

* disable cases

* add macro to disable cases

* fix typo

* print platform

* remove condition