Use stringToUTF8 instead of deprecated writeStringToMemory

Author: axic

wrapper.js

@@ -14,8 +14,9 @@ function setupMethods (soljson) {
   var compileStandard = null;
   if (('_compileJSONCallback' in soljson) || ('_compileStandard' in soljson)) {
     var copyString = function (str, ptr) {
-      var buffer = soljson._malloc(str.length + 1);
-      soljson.writeStringToMemory(str, buffer);
+      var length = soljson.lengthBytesUTF8(str);
+      var buffer = soljson._malloc(length + 1);
+      soljson.stringToUTF8(str, buffer, length + 1);
       soljson.setValue(ptr, buffer, '*');
     };
     var wrapCallback = function (callback) {