Isolated emscripten in new lib

lib/emscripten/emtests/test_stdvec.c

@@ -0,0 +1,32 @@
+/*
+ * 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 <vector>
+#include <stdio.h>
+
+struct S {
+  int a;
+  float b;
+};
+
+void foo(int a, float b) { printf("%d:%.2f\n", a, b); }
+
+int main(int argc, char *argv[]) {
+  std::vector<S> ar;
+  S s;
+
+  s.a = 789;
+  s.b = 123.456f;
+  ar.push_back(s);
+
+  s.a = 0;
+  s.b = 100.1f;
+  ar.push_back(s);
+
+  foo(ar[0].a, ar[0].b);
+  foo(ar[1].a, ar[1].b);
+}