test: skip c++ example for all platforms but linux

test.sh

@@ -38,7 +38,7 @@ validate () {
     time cargo check $@ --no-default-features
     time cargo check $@ --manifest-path util/io/Cargo.toml --no-default-features
     time cargo check $@ --manifest-path util/io/Cargo.toml --features "mio"
-  
+
     # Validate chainspecs
     echo "________Validate chainspecs________"
     time ./scripts/validate_chainspecs.sh
@@ -48,17 +48,24 @@ validate () {
 }
 
 cpp_test () {
-  # Running the C++ example
-  echo "________Running the C++ example________"
-  cd parity-clib-examples/cpp && \
-    mkdir -p build && \
-    cd build && \
-    cmake .. && \
-    make -j $THREADS && \
-    ./parity-example && \
-    cd .. && \
-    rm -rf build && \
-    cd ../..
+  case $CARGO_TARGET in
+    (x86_64-unknown-linux-gnu)
+      # Running the C++ example
+      echo "________Running the C++ example________"
+      cd parity-clib-examples/cpp && \
+        mkdir -p build && \
+        cd build && \
+        cmake .. && \
+        make -j $THREADS && \
+        ./parity-example && \
+        cd .. && \
+        rm -rf build && \
+        cd ../..
+      ;;
+    (*)
+      echo "________Skipping the C++ example________"
+      ;;
+  esac
 }
 
 cargo_test () {