Cleanup temporary files after source map generation.

Summary:
Changelog:
[iOS][Fixed] - When source maps are enabled, clean up temporary files from the build directory. Reduces bundle size by at least 1MB.

Reviewed By: cipolleschi

Differential Revision: D38866158

fbshipit-source-id: 0f46faf4e767bb7417b24f283fbe19cfa022941a

Author: Dmitry Rykun

scripts/react-native-xcode.sh

@@ -170,6 +170,8 @@ else
   if [[ $EMIT_SOURCEMAP == true ]]; then
     HBC_SOURCEMAP_FILE="$DEST/main.jsbundle.map"
     "$NODE_BINARY" "$COMPOSE_SOURCEMAP_PATH" "$PACKAGER_SOURCEMAP_FILE" "$HBC_SOURCEMAP_FILE" -o "$SOURCEMAP_FILE"
+    rm "$HBC_SOURCEMAP_FILE"
+    rm "$PACKAGER_SOURCEMAP_FILE"
   fi
   BUNDLE_FILE="$DEST/main.jsbundle"
 fi