Isolated emscripten in new lib

lib/emscripten/emtests/test_getopt.c

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2016 The Emscripten Authors.  All rights reserved.
+ * Emscripten is available under two separate licenses, the MIT license and the
+ * University of Illinois/NCSA Open Source License.  Both these licenses can be
+ * found in the LICENSE file.
+ */
+
+#pragma clang diagnostic ignored "-Winvalid-pp-token"
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+
+int main(int argc, char *argv[]) {
+  int flags, opt;
+  int nsecs, tfnd;
+
+  nsecs = 0;
+  tfnd = 0;
+  flags = 0;
+  while ((opt = getopt(argc, argv, "nt:")) != -1) {
+    switch (opt) {
+      case 'n':
+        flags = 1;
+        break;
+      case 't':
+        nsecs = atoi(optarg);
+        tfnd = 1;
+        break;
+      default: /* '?' */
+        fprintf(stderr, "Usage: %s [-t nsecs] [-n] name\n", argv[0]);
+        exit(EXIT_FAILURE);
+    }
+  }
+
+  printf("flags=%d; tfnd=%d; optind=%d\n", flags, tfnd, optind);
+
+  if (optind >= argc) {
+    fprintf(stderr, "Expected argument after options\n");
+    exit(EXIT_FAILURE);
+  }
+
+  printf("name argument = %s\n", argv[optind]);
+
+  /* Other code omitted */
+
+  exit(EXIT_SUCCESS);
+}