[modules] Disable HTML-like comments

test/mjsunit/harmony/modules-html-comments.js

+// Copyright 2016 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+//
+// Flags: --allow-natives-syntax
+//
+// MODULE
+
+var x = 1;
+x --> 0;
+assertEquals(0, x, 'a');
+
+var x = 0; x <!-- x
+assertEquals(-1, x, 'b');
+
+var x = 1; x <!--x
+assertEquals(0, x, 'c');
+
+var x = 2; x <!-- x; x = 42;
+assertEquals(42, x, 'd');
+
+var x = 1; x <! x--;
+assertEquals(0, x, 'e');
+
+var x = 1; x <!- x--;
+assertEquals(0, x, 'f');
+
+var b = true <! true;
+assertFalse(b, 'g');
+
+var b = true <!- true;
+assertFalse(b, 'h');
+
+function f() {
+  var x = 9;
+  x --> 0 && 0 <!-- x;
+  return x;
+}
+
+%DeoptimizeFunction(f);
+
+assertEquals(f(), 7);
+
+%OptimizeFunctionOnNextCall(f);
+
+assertEquals(f(), 7);