Allow use of SignalFd through shared reference #929

Job	Run time
macos-aarch64	1m 54s
linux_native_builds (x86_64-unknown-linux-gnu)	2m 30s
check_new_changelog	5s
macos	3m 37s
linux_native_builds (x86_64-unknown-linux-musl)	2m 33s
minver	15s
rust_stable	1m 13s
tier3 (x86_64-unknown-dragonfly)	58s
rustfmt	12s
tier3 (x86_64-unknown-openbsd)	57s
tier3 (x86_64-unknown-haiku)	55s
redox	38s
cross (arm-unknown-linux-gnueabi)	1m 39s
cross_compiling (aarch64-linux-android)	35s
cross (armv7-unknown-linux-gnueabihf)	1m 36s
cross_compiling (arm-linux-androideabi)	32s
cross (i686-unknown-linux-gnu)	1m 33s
cross_compiling (armv7-linux-androideabi)	32s
cross (i686-unknown-linux-musl)	1m 43s
cross_compiling (i686-linux-android)	30s
cross (mips-unknown-linux-gnu)	1m 38s
cross_compiling (x86_64-linux-android)	32s
cross (mips64-unknown-linux-gnuabi64)	1m 41s
cross_compiling (arm-unknown-linux-musleabi)	34s
cross (mips64el-unknown-linux-gnuabi64)	1m 37s
cross_compiling (x86_64-unknown-fuchsia)	25s
cross (mipsel-unknown-linux-gnu)	1m 41s
cross_compiling (x86_64-unknown-illumos)	25s
cross (powerpc64le-unknown-linux-gnu)	1m 36s
cross_compiling (aarch64-apple-ios, true)	27s
cross_compiling (powerpc64-unknown-linux-gnu)	35s
cross_compiling (s390x-unknown-linux-gnu)	34s
cross_compiling (x86_64-unknown-linux-gnux32)	33s
cross_compiling (x86_64-unknown-netbsd)	26s
	37m 11s

Provide feedback