Isolated emscripten in new lib

lib/emscripten/emtests/test_funcs.c

@@ -0,0 +1,13 @@
+/*
+ * 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>
+int funcy(int x) { return x * 9; }
+int main() {
+  printf("*%d,%d*\n", funcy(8), funcy(10));
+  return 0;
+}