add cargo-all-features to container

Some crates have a myriad of features, and it is very easy to
accidentally mess up imports in a way that `cargo check --all-features`
works, but only compiling with only a subset of features breaks. For
this scenario, cargo check-all-features can help, as it will attempt to
compile all feature permutations.

We can even add this to the default CI, even for crates like vhost that
have incompatible features, due to cargo-all-features allowing the
elimination of incompatible features from the test matrix [1].

Some usecases where this could have been helpful is in vm-memory, where
we have tens of feature permutations, and some of them invariably get
broken regularly [2], or in crates that have no-std support that is
offered via an opt-out 'std' feature [3]

[1]: https://crates.io/crates/cargo-all-features#options
[2]: rust-vmm/vm-memory#350
[3]: rust-vmm/vm-allocator#107

Signed-off-by: Patrick Roy <[email protected]>

Author: roypat

build_container.sh

@@ -98,6 +98,8 @@ if [ "$ARCH" != "riscv64" ]; then
     popd
 fi
 
+cargo install cargo-all-features
+
 # Install some dependencies required by vhost-device crates but not available
 # in Ubuntu repos.
 # Some of these do not support riscv64, since vhost-device crates do not