Remove some unsafe code; fix a soundness hole #1280

Job	Run time
Windows AArch64	57s
Miri	2m 30s
iOS (aarch64-apple-ios)	20s
iOS (x86_64-apple-ios)	24s
iOS (aarch64-apple-ios-macabi)	18s
MSRV (ubuntu-24.04)	20s
MSRV (windows-latest)	34s
Test (windows-latest, nightly-x86_64-gnu)	2m 26s
Test (ubuntu-24.04, stable)	2m 23s
Build Targets (wasm32-unknown-unknown)	23s
Test (ubuntu-24.04, beta)	3m 11s
Test (windows-latest, stable-x86_64-gnu)	2m 17s
Test (windows-latest, nightly-i686-msvc)	2m 43s
Test (ubuntu-24.04, nightly)	2m 51s
Build Targets (wasm32-wasip1)	23s
Test (windows-latest, stable-x86_64-msvc)	1m 52s
Test (macos-latest, nightly)	3m 35s
Test (windows-latest, stable-i686-msvc)	2m 40s
Build Targets (x86_64-fortanix-unknown-sgx)	21s
Test (windows-latest, nightly-x86_64-msvc)	1m 52s
Rustfmt	10s
Build Targets (x86_64-unknown-fuchsia)	22s
Build Targets (x86_64-unknown-illumos)	22s
Test (macos-latest, stable)	1m 50s
Docker (i586-unknown-linux-gnu)	41s
Docker (arm-unknown-linux-gnueabihf)	45s
Docker (powerpc64-unknown-linux-gnu)	52s
Docker (armv7-unknown-linux-gnueabihf)	48s
Docker (i686-unknown-linux-gnu)	39s
Docker (x86_64-pc-windows-gnu)	48s
Docker (aarch64-unknown-linux-gnu)	1m 6s
Docker (aarch64-linux-android)	1m 44s
Docker (x86_64-unknown-linux-gnu)	34s
Docker (x86_64-unknown-linux-musl)	38s
Docker (x86_64-linux-android)	1m 22s
Docker (i686-linux-android)	1m 51s
Docker (arm-linux-androideabi)	2m 55s
Docker (armv7-linux-androideabi)	3m 9s
Docker (s390x-unknown-linux-gnu)	49s
	53m 45s

Provide feedback