* codecov for arm32 aarch64, vs2017 ci

* vs2017 default to x86 even on x64 host

* set cmake NCNN_BUILD_TESTS default off and add -DNCNN_BUILD_TESTS=ON to ci

* runtime cpu dispatch

* force thread one

* disable openmp for coverage

* simplify test layer

* print NCNN_TARGET_ARCH

* less ci build variants

* weight fp16 storage option

* test convdw int8

* apple a12 a13

* ncnn_add_layer ncnn_add_shader cmake macro

* enable image storage test

* update swiftshader, use subzero backend, opt default

* wip

* wip

* fix

* image and imageview can not be destroyed until command execution ends

* fast copy path for tightly packed data

* wip

* texture load works

* 1d 3d image

* record clone image, multiple commands share one image reference

* upload download image

* layer forward accept vkimagemat

* vkimagemat graph works

* staging vkimagemat for passing dynamic parameters, macro for fp32+image shader, padding image shader

* vkimagemat elemsize

* convolution test pass

* conv1x1s1 image shader

* fast staging image allocator from host memory, pooling image shader

* convolutiondepthwise image shader

* innerproduct image shader

* packing image shader

* crop deconvolution image shader

* resolve spirv binding types

* image fp16 and fp16a, cast image shader

* eltwise image shader

* wip

* absval image shader

* deconvolutiondepthwise image shader

* concat image shader, squeezenet works

* noop split image shader

* uniform precision hint

* layer support_image_storage

* wip

* vulkan device utility operator

* command is storage and packing option aware

* fallback to cpu on image allocation failed, mobilenetssd works

* flatten image shader, enable more test

* ci test

* check imgfp32 imgfp16 imgfp16a features

* fix ci test

* fix ci test

* upgrade swiftshader

* wip

* opt aggressive

* imgfp16p

* opt none

* convolution winograd image shader

* fix flush range, fast copy path for continous buffer

* minor fix

* fix innerproduct

* wip ...

* wip

* cast fix

* packing test

* wip

* image fp16p is fp16p

* wip

* silence

* more line info

* code clean

* softmax image shader

* try checkout v2 to resolve some ci issue

* coverage

* wip

* use relative path

* enable gpu test

* restore jobs

* codecov