Support more cross targets

Adds support for Android, Linux/ARM, and windows. Bare-metal thumb targets are listed,
because they're supported by cross, but they aren't enabled by default as they don't
support std and will likely not be used by most projects.

I've left off the *linux-musleabi* targets as they are failing with an odd error that
is likely due to musl itself.

Additionally I've left out iOS targets as that support needs to be added to trust before
it should be added here.

.travis.yml

@@ -18,8 +18,28 @@ matrix:
   # TODO These are all the build jobs. Adjust as necessary. Comment out what you
   # don't need
   include:
+    # Android
+    - env: TARGET=aarch64-linux-android DISABLE_TESTS=1
+    - env: TARGET=arm-linux-androideabi DISABLE_TESTS=1
+    - env: TARGET=armv7-linux-androideabi DISABLE_TESTS=1
+    - env: TARGET=i686-linux-android DISABLE_TESTS=1
+    - env: TARGET=x86_64-linux-android DISABLE_TESTS=1
+
+    # iOS
+    - env: TARGET=aarch64-apple-ios DISABLE_TESTS=1
+      os: osx
+    - env: TARGET=armv7-apple-ios DISABLE_TESTS=1
+      os: osx
+    - env: TARGET=armv7s-apple-ios DISABLE_TESTS=1
+      os: osx
+    - env: TARGET=i386-apple-ios DISABLE_TESTS=1
+      os: osx
+    - env: TARGET=x86_64-apple-ios DISABLE_TESTS=1
+      os: osx
+
     # Linux
     - env: TARGET=aarch64-unknown-linux-gnu
+    - env: TARGET=arm-unknown-linux-gnueabi
     - env: TARGET=armv7-unknown-linux-gnueabihf
     - env: TARGET=i686-unknown-linux-gnu
     - env: TARGET=i686-unknown-linux-musl
@@ -45,6 +65,16 @@ matrix:
     - env: TARGET=x86_64-unknown-freebsd DISABLE_TESTS=1
     - env: TARGET=x86_64-unknown-netbsd DISABLE_TESTS=1
 
+    # Windows
+    - env: TARGET=x86_64-pc-windows-gnu
+
+    # Bare metal
+    # These targets don't support std and as such are likely not suitable for
+    # most crates.
+    # - env: TARGET=thumbv6m-none-eabi
+    # - env: TARGET=thumbv7em-none-eabi
+    # - env: TARGET=thumbv7em-none-eabihf
+    # - env: TARGET=thumbv7m-none-eabi
 
     # Testing other channels
     - env: TARGET=x86_64-unknown-linux-gnu

README.md

@@ -120,6 +120,32 @@ check if using a newer release (see `ci/install.sh`)
 would
 [fix your problem](https://github.com/japaric/cross/blob/master/CHANGELOG.md).
 
+### Android
+
+- aarch64-linux-android
+
+- arm-linux-androideabi
+
+- armv7-linux-androideabi
+
+- i686-linux-android
+
+- x86_64-linux-android
+
+### iOS
+
+- aarch64-apple-ios
+
+- armv7-apple-ios
+
+- armv7s-apple-ios
+
+- i386-apple-ios
+
+- x86_64-apple-ios
+
+### Linux
+
 - `i686-unknown-linux-gnu`
 
 - `i686-unknown-linux-musl`
@@ -130,6 +156,8 @@ would
 
 - `aarch64-unknown-linux-gnu`
 
+- `arm-unknown-linux-gnueabi`
+
 - `armv7-unknown-linux-gnueabihf`
 
 - `mips-unknown-linux-gnu`

ci/install.sh

@@ -10,6 +10,26 @@ main() {
         sort=gsort  # for `sort --sort-version`, from brew's coreutils.
     fi
 
+    # Builds for iOS are done on OSX, but require the specific target to be
+    # installed.
+    case $TARGET in
+        aarch64-apple-ios)
+            rustup target install aarch64-apple-ios
+            ;;
+        armv7-apple-ios)
+            rustup target install armv7-apple-ios
+            ;;
+        armv7s-apple-ios)
+            rustup target install armv7s-apple-ios
+            ;;
+        i386-apple-ios)
+            rustup target install i386-apple-ios
+            ;;
+        x86_64-apple-ios)
+            rustup target install x86_64-apple-ios
+            ;;
+    esac
+
     # This fetches latest stable release
     local tag=$(git ls-remote --tags --refs --exit-code https://github.com/japaric/cross \
                        | cut -d/ -f3 \