Build

Add `efi_rng` opt-in backend #203

Job	Run time
Cross (sparcv9-sun-solaris)	33s
UEFI RNG Protocol (aarch64-unknown-uefi)	30s
Cross (x86_64-unknown-illumos)	25s
Linux x32 (x86_64-unknown-linux-gnux32)	31s
UEFI RNG Protocol (x86_64-unknown-uefi)	29s
UEFI RNG Protocol (i686-unknown-uefi)	29s
Apple Other	1m 12s
RDRAND UEFI (x86_64-unknown-uefi)	33s
RDRAND UEFI (i686-unknown-uefi)	33s
RNDR	14s
Tier 2 (x86_64-unknown-fuchsia)	14s
Tier 2 (x86_64-unknown-redox)	9s
Tier 3 (aarch64-kmc-solid_asp3)	22s
Tier 2 (x86_64-fortanix-unknown-sgx)	35s
Web no_std	28s
Tier 3 (aarch64-unknown-nto-qnx710)	24s
Web no_std with Atomics	30s
Tier 3 (armv6k-nintendo-3ds)	24s
Web	34s
ESP-IDF	21s
Tier 3 (armv7-sony-vita-newlibeabihf)	21s
Web with Atomics	34s
Tier 3 (i686-unknown-hurd-gnu)	22s
WasmV1 no_std	24s
Tier 3 (x86_64-unknown-hermit)	22s
No Atomics	14s
WasmV1 no_std with Atomics	33s
Tier 3 (x86_64-wrs-vxworks)	22s
Tier 3 (x86_64-unknown-dragonfly)	23s
Tier 3 (x86_64-unknown-haiku)	25s
	13m 30s

Provide feedback