Cleanup interface descriptors to reflect that vectors are part of loads.

src/runtime.js

Index: src/runtime.js
diff --git a/src/runtime.js b/src/runtime.js
index ab79a4bbde0853ee3f39b68c2cf8518fb8f8f975..f732b7528c8dfbd769eeac00bec9a09021121092 100644
--- a/src/runtime.js
+++ b/src/runtime.js
@@ -760,7 +760,9 @@ TO_NAME = function TO_NAME() {
    -----------------------------------------------
 */
 
-StringLengthTF_STUB = function StringLengthTF_STUB(receiver, name) {
+StringLengthTF_STUB = function StringLengthTF_STUB(receiver, name, i, v) {
+  // i and v are dummy parameters mandated by the InterfaceDescriptor,
+  // (LoadWithVectorDescriptor).
   return %_StringGetLength(%_JSValueGetValue(receiver));
 }