Sync x86 chkstk intrinsics with LLVM #772

Job	Run time
Clippy	16s
Rustfmt	8s
Test (aarch64-unknown-linux-gnu, ubuntu-latest, nightly)	1m 51s
Test (arm-unknown-linux-gnueabi, ubuntu-latest, nightly)	1m 31s
Test (arm-unknown-linux-gnueabihf, ubuntu-latest, nightly)	1m 25s
Test (i586-unknown-linux-gnu, ubuntu-latest, nightly)	1m 5s
Test (i686-unknown-linux-gnu, ubuntu-latest, nightly)	1m 13s
Test (powerpc-unknown-linux-gnu, ubuntu-latest, nightly)	1m 28s
Test (powerpc64-unknown-linux-gnu, ubuntu-latest, nightly)	1m 35s
Test (powerpc64le-unknown-linux-gnu, ubuntu-latest, nightly)	1m 24s
Test (thumbv6m-none-eabi, ubuntu-latest, nightly)	59s
Test (thumbv7em-none-eabi, ubuntu-latest, nightly)	1m 8s
Test (thumbv7em-none-eabihf, ubuntu-latest, nightly)	58s
Test (thumbv7m-none-eabi, ubuntu-latest, nightly)	1m 7s
Test (wasm32-unknown-unknown, ubuntu-latest, nightly)	1m 16s
Test (x86_64-unknown-linux-gnu, ubuntu-latest, nightly)	1m 9s
Test (x86_64-apple-darwin, macos-latest, nightly)	1m 36s
Test (i686-pc-windows-msvc, windows-latest, nightly)	2m 0s
Test (x86_64-pc-windows-msvc, windows-latest, nightly)	1m 49s
Test (i686-pc-windows-gnu, windows-latest, nightly-i686-gnu)	2m 18s
Test (x86_64-pc-windows-gnu, windows-latest, nightly-x86_64-gnu)	2m 14s
success	1s
	28m 31s

Provide feedback