Add option for publish

Keeping this hidden until I hear back what it's used for in source build

Author: John Luo

eng/build.sh

@@ -18,6 +18,7 @@ verbosity='minimal'
 run_restore=''
 run_build=true
 run_pack=false
+run_publish=false
 run_tests=false
 build_all=false
 build_deps=true
@@ -147,6 +148,9 @@ while [[ $# -gt 0 ]]; do
         -pack)
             run_pack=true
             ;;
+        -public)
+            run_publish=true
+            ;;
         -no-pack|-nopack)
             run_pack=false
             ;;