[CI] Test on s390x-unknown-linux-gnu target (#270)

Author: joshlf

.github/workflows/ci.yml

@@ -32,7 +32,17 @@ jobs:
         # See `INTERNAL.md` for an explanation of these pinned toolchain
         # versions.
         toolchain: [ "msrv", "stable", "nightly" ]
-        target: [ "i686-unknown-linux-gnu", "x86_64-unknown-linux-gnu", "arm-unknown-linux-gnueabi", "aarch64-unknown-linux-gnu", "powerpc-unknown-linux-gnu", "powerpc64-unknown-linux-gnu", "riscv64gc-unknown-linux-gnu", "wasm32-wasi" ]
+        target: [
+          "i686-unknown-linux-gnu",
+          "x86_64-unknown-linux-gnu",
+          "arm-unknown-linux-gnueabi",
+          "aarch64-unknown-linux-gnu",
+          "powerpc-unknown-linux-gnu",
+          "powerpc64-unknown-linux-gnu",
+          "riscv64gc-unknown-linux-gnu",
+          "s390x-unknown-linux-gnu",
+          "wasm32-wasi"
+        ]
         features: [ "--no-default-features", "", "--features __internal_use_only_features_that_work_on_stable", "--all-features" ]
         crate: [ "zerocopy", "zerocopy-derive" ]
         exclude: