Remove --harmony-modules flag and let embedder decide when modules are used

test/mjsunit/harmony/module-parsing-eval.js

Index: test/mjsunit/harmony/module-parsing-eval.js
diff --git a/test/mjsunit/harmony/module-parsing-eval.js b/test/mjsunit/harmony/module-parsing-eval.js
index fa9e5ec35ca77ed0b26e71cd463003f70c3c7961..6c080dbf446254ab64aa970a86108226c51179b7 100644
--- a/test/mjsunit/harmony/module-parsing-eval.js
+++ b/test/mjsunit/harmony/module-parsing-eval.js
@@ -25,8 +25,6 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Flags: --harmony-modules
-
 // Check that import/export declarations are rejected in eval or local scope.
 assertThrows("export let x;", SyntaxError);
 assertThrows("import x from 'http://url';", SyntaxError);