fix emscripten dependencies by making separate test crate

lib/emscripten-tests/emtests/test_mod_globalstruct.c

@@ -0,0 +1,25 @@
+/*
+ * 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>
+
+struct malloc_params {
+  size_t magic, page_size;
+};
+
+malloc_params mparams;
+
+#define SIZE_T_ONE ((size_t)1)
+#define page_align(S) \
+  (((S) + (mparams.page_size - SIZE_T_ONE)) & ~(mparams.page_size - SIZE_T_ONE))
+
+int main() {
+  mparams.page_size = 4096;
+  printf("*%d,%d,%d,%d*\n", mparams.page_size, page_align(1000),
+         page_align(6000), page_align(66474));
+  return 0;
+}