* 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

* update roialign

* update tool for roialign

* fix ceil for roialign

* fix ios build

* fix

* fix

* make it compatibile with the old version

* fix ios build

* trigger CI

* fix test

* order

* build

* remove code

* merge roialign

* accelerate ROIAlign

* update note

* rename func

* roialign version

* trigger CI

* fix roialign

* use ref for pre-calc in roialign

* retrigger CI

* pre-alloc