Remove GetDefaultReceiver, pass in undefined to sloppy-mode functions instead.

src/harmony-typedarray.js

Index: src/harmony-typedarray.js
diff --git a/src/harmony-typedarray.js b/src/harmony-typedarray.js
index 7fc01cb801a9e6470899c042a9f09ce9a6c3992d..5c735fd9576b5c54cc14063a9b2bb24554290825 100644
--- a/src/harmony-typedarray.js
+++ b/src/harmony-typedarray.js
@@ -41,9 +41,9 @@ function NAMEForEach(f /* thisArg */) {  // length == 1
   }
 
   var needs_wrapper = false;
-  if (IS_NULL_OR_UNDEFINED(receiver)) {
-    receiver = %GetDefaultReceiver(f) || receiver;
-  } else {
+  if (IS_NULL(receiver)) {
+    if (%IsSloppyModeFunction(mapfn)) receiver = UNDEFINED;
+  } else if (!IS_UNDEFINED(receiver)) {
     needs_wrapper = SHOULD_CREATE_WRAPPER(f, receiver);
   }