Add hexagon support #691

Job	Run time
Rustfmt	9s
Test (aarch64-unknown-linux-gnu, ubuntu-latest, nightly)	2m 12s
Clippy	13s
Test (arm-unknown-linux-gnueabi, ubuntu-latest, nightly)	1m 47s
Test (arm-unknown-linux-gnueabihf, ubuntu-latest, nightly)	1m 55s
Test (i586-unknown-linux-gnu, ubuntu-latest, nightly)	1m 26s
Test (i686-unknown-linux-gnu, ubuntu-latest, nightly)	1m 35s
Test (powerpc-unknown-linux-gnu, ubuntu-latest, nightly)	1m 58s
Test (powerpc64-unknown-linux-gnu, ubuntu-latest, nightly)	1m 53s
Test (powerpc64le-unknown-linux-gnu, ubuntu-latest, nightly)	1m 47s
Test (thumbv6m-none-eabi, ubuntu-latest, nightly)	1m 23s
Test (thumbv7em-none-eabi, ubuntu-latest, nightly)	1m 25s
Test (thumbv7em-none-eabihf, ubuntu-latest, nightly)	1m 34s
Test (thumbv7m-none-eabi, ubuntu-latest, nightly)	1m 17s
Test (wasm32-unknown-unknown, ubuntu-latest, nightly)	1m 31s
Test (x86_64-unknown-linux-gnu, ubuntu-latest, nightly)	1m 33s
Test (x86_64-apple-darwin, macos-latest, nightly)	2m 23s
Test (i686-pc-windows-msvc, windows-latest, nightly)	2m 12s
Test (x86_64-pc-windows-msvc, windows-latest, nightly)	2m 7s
Test (i686-pc-windows-gnu, windows-latest, nightly-i686-gnu)	2m 44s
Test (x86_64-pc-windows-gnu, windows-latest, nightly-x86_64-gnu)	2m 39s
	35m 43s

Provide feedback