Isolated emscripten in new lib

lib/emscripten/emtests/test_nested_struct_varargs.c

@@ -0,0 +1,52 @@
+/*
+ * Copyright 2014 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 <stdarg.h>
+
+struct A {
+  int x;
+};
+
+struct B {
+  double x;
+};
+
+struct C {
+  char c[9];
+  struct A a;
+  struct B b;
+};
+
+void foo(int unused, ...)
+{
+  va_list vl;
+  va_start(vl, unused);
+  struct C c = va_arg(vl, struct C);
+  va_end(vl);
+
+  printf("%d\n", c.a.x);
+  printf("%f\n", c.b.x);
+  printf("%s\n", c.c);
+}
+
+int main() {
+  struct A a = {
+    .x = 42,
+  };
+  struct B b = {
+    .x = 42.314,
+  };
+  struct C c = {
+    .a = a,
+    .b = b,
+    .c = "nicetest",
+  };
+  foo(0, c);
+  return 0;
+}
+