1: fix cmake cross-ios failed caused by df118a87
build static lib for APPLE define for XCODE third_party framework including require
2: megbrain_test/megdnn_test build when MGE_INFERENCE_ONLY=ON
now u can build megbrain_test/megdnn_test by:
EXTRA_CMAKE_ARGS="-DMGE_WITH_TEST=ON" ./scripts/cmake-build/xxx.sh
example macos-cross-ios build megdnn_test for IOS by
EXTRA_CMAKE_ARGS="-DMGE_WITH_TEST=ON" ./scripts/cmake-build/cross_build_ios_arm_inference.sh
3: reuse host flatc build when cross build mode
GitOrigin-RevId: 132f4bf893567bdb1d54de506449950513a5841f