- removed the 'use strip' extension

- removed the JS_EVAL_FLAG_STRIP eval flag and replaced it with JS_SetStripInfo() which has simpler semantics.
- qjs: added the '-s' and '--strip-source' options
- qjsc: added the '-s' and '--keep-source' options

repl.js

@@ -22,8 +22,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
-"use strip";
-
 import * as std from "std";
 import * as os from "os";