ci: Build the base system after bootstraping the toolchain

The previous sanity check command was incorrect. Furthermore, it's
better to bootstrap the whole base system to make sure that
the toolchain works.

Signed-off-by: Michal Rostecki <[email protected]>

.github/workflows/crossdev.yml

@@ -17,6 +17,35 @@ jobs:
         target:
           - aarch64-unknown-linux-gnu
           - aarch64-unknown-linux-musl
+          - arm-unknown-linux-gnueabi
+          - arm-unknown-linux-gnueabihf
+          - arm-unknown-linux-musleabi
+          - arm-unknown-linux-musleabihf
+          - armv7-unknown-linux-gnueabi
+          - armv7-unknown-linux-gnueabihf
+          - mips-unknown-linux-gnu
+          - mips-unknown-linux-musl
+          - mipsel-unknown-linux-gnu
+          - mipsel-unknown-linux-musl
+          - mips64-unknown-linux-gnu
+          - mips64-unknown-linux-musl
+          - mips64el-unknown-linux-gnu
+          - mips64el-unknown-linux-musl
+          - powerpc-unknown-linux-gnu
+          - powerpc-unknown-linux-musl
+          - powerpc64-unknown-linux-gnu
+          - powerpc64-unknown-linux-musl
+          - riscv32-unknown-linux-gnu
+          - riscv32-unknown-linux-musl
+          - riscv64-unknown-linux-gnu
+          - riscv64-unknown-linux-musl
+          - sparc-unknown-linux-gnu
+          - sparc64-unknown-linux-gnu
+          - sparc64-unknown-linux-musl
+          - s390x-unknown-linux-gnu
+          - s390x-unknown-linux-musl
+          - x86_64-unknown-linux-gnu
+          - x86_64-unknown-linux-musl
         stage3:
           - latest # `openrc` (glibc+GCC) is tagged as `latest`
           - musl
@@ -44,5 +73,5 @@ jobs:
 
             # zstd and its dependencies need both C and C++ toolchain. If any of them
             # is broken, the installation will fail.
-            run: ${{ matrix.target }}-emerge app-arch/zstd
+            ${{ matrix.target }}-emerge @system
             "