Isolated emscripten in new lib

lib/emscripten/emtests/test_libgen.c

@@ -0,0 +1,46 @@
+/*
+ * 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.
+ */
+
+#include <stdio.h>
+#include <libgen.h>
+
+int main() {
+  char p1[16] = "/usr/lib", p1x[16] = "/usr/lib";
+  printf("%s -> ", p1);
+  printf("%s : %s\n", dirname(p1x), basename(p1));
+
+  char p2[16] = "/usr", p2x[16] = "/usr";
+  printf("%s -> ", p2);
+  printf("%s : %s\n", dirname(p2x), basename(p2));
+
+  char p3[16] = "/usr/", p3x[16] = "/usr/";
+  printf("%s -> ", p3);
+  printf("%s : %s\n", dirname(p3x), basename(p3));
+
+  char p4[16] = "/usr/lib///", p4x[16] = "/usr/lib///";
+  printf("%s -> ", p4);
+  printf("%s : %s\n", dirname(p4x), basename(p4));
+
+  char p5[16] = "/", p5x[16] = "/";
+  printf("%s -> ", p5);
+  printf("%s : %s\n", dirname(p5x), basename(p5));
+
+  char p6[16] = "///", p6x[16] = "///";
+  printf("%s -> ", p6);
+  printf("%s : %s\n", dirname(p6x), basename(p6));
+
+  char p7[16] = "/usr/../lib/..", p7x[16] = "/usr/../lib/..";
+  printf("%s -> ", p7);
+  printf("%s : %s\n", dirname(p7x), basename(p7));
+
+  char p8[16] = "", p8x[16] = "";
+  printf("(empty) -> %s : %s\n", dirname(p8x), basename(p8));
+
+  printf("(null) -> %s : %s\n", dirname(0), basename(0));
+
+  return 0;
+}