Add libsodium source

libsodium-1.0.18-RELEASE/test/default/pre.js.inc

@@ -0,0 +1,22 @@
+try {
+    this['Module'] = Module;
+    Module.test;
+} catch(e) {
+    this['Module'] = Module = {};
+}
+if (typeof process === 'object') {
+    if (typeof(FS) === 'object') {
+        Module['preRun'] = Module['preRun'] || [];
+        Module['preRun'].push(function() {
+            FS.init();
+            FS.mkdir('/test-data');
+            FS.mount(NODEFS,  { root: '.' }, '/test-data');
+        });
+    }
+} else {
+    Module['print'] = function(x) {
+        var event = new Event('test-output');
+        event.data = x;
+        window.dispatchEvent(event);
+    };
+}