Merge branch 'cbindgen' into 'master'

Add checks and install cbindgen in bootstrap.sh.

See merge request redox-os/redox!1389

bootstrap.sh

@@ -1024,9 +1024,10 @@ fi
 
 cargoInstall cargo-config 0.1.1
 cargoInstall just 1.16.0
+cargoInstall cbindgen 0.26.0
 
 if [ "$dependenciesonly" = false ]; then
 	boot
 fi
 
-echo "Redox bootstrap complete!"
+echo "Redox bootstrap complete!"

mk/depends.mk

@@ -7,6 +7,10 @@ ifeq ($(shell which rustup),)
 $(error rustup not found, install from "https://rustup.rs/")
 endif
 
+ifeq ($(shell which cbindgen),)
+$(error cbindgen not found, install from crates.io or from your package manager)
+endif
+
 ifeq ($(shell which nasm),)
 $(error nasm not found, install from your package manager)
 endif