Add CI on Github Actions for macOS #181

Job	Run time
build-native-gcc	4m 3s
build-native-llvm	5m 58s
test-native-gcc	8m 42s
build-aarch64-gcc	7m 51s
test-native-llvm	7m 48s
build-aarch64-llvm	3m 12s
build-armhf-gcc	4m 39s
build-armhf-llvm	1m 41s
build-ppc64el-gcc	6m 46s
build-ppc64el-llvm	4m 15s
build-s390x-gcc	5m 1s
build-s390x-llvm	2m 30s
build-riscv64-llvm	3m 0s
test-aarch64-gcc (qemu_cpu: "max,sve=off")	18m 41s
test-aarch64-gcc (qemu_cpu: "max,sve=on,sve128=on")	22m 49s
test-aarch64-gcc (qemu_cpu: "max,sve=on,sve256=on")	25m 41s
test-aarch64-gcc (qemu_cpu: "max,sve=on,sve512=on")	30m 48s
test-aarch64-llvm (qemu_cpu: "max,sve=off")	16m 27s
test-aarch64-llvm (qemu_cpu: "max,sve=on,sve128=on")	24m 53s
test-aarch64-llvm (qemu_cpu: "max,sve=on,sve256=on")	25m 38s
test-aarch64-llvm (qemu_cpu: "max,sve=on,sve512=on")	29m 32s
test-armhf-gcc (qemu_cpu: "max")	14m 20s
test-armhf-llvm (qemu_cpu: "max")	16m 28s
test-ppc64el-gcc (qemu_cpu: "power10")	30m 29s
test-ppc64el-llvm (qemu_cpu: "power10")	28m 13s
test-s390x-gcc (qemu_cpu: "")	22m 55s
test-s390x-llvm (qemu_cpu: "")	19m 28s
test-riscv64-llvm (qemu_cpu: "rv64,zba=true,zbb=true,zbs=true,v=false")	15m 54s
test-riscv64-llvm (qemu_cpu: "rv64,zba=true,zbb=true,zbs=true,v=true,vlen=128,elen=64,vext_spec=v1.0")	29m 58s
test-riscv64-llvm (qemu_cpu: "rv64,zba=true,zbb=true,zbs=true,v=true,vlen=256,elen=64,vext_spec=v1.0")	44m 16s
test-riscv64-llvm (qemu_cpu: "rv64,zba=true,zbb=true,zbs=true,v=true,vlen=512,elen=64,vext_spec=v1.0")	59m 9s
	9h 1m 5s

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