Clean up some "GetProperty" methods/functions.

src/execution.cc

Index: src/execution.cc
diff --git a/src/execution.cc b/src/execution.cc
index 7442d1732fb42c1f6db538000c71730f6562b31a..fccb4bf3341c2a21b372cf16bef171c093da06d7 100644
--- a/src/execution.cc
+++ b/src/execution.cc
@@ -783,8 +783,8 @@ Handle<Object> Execution::CharAt(Handle<String> string, uint32_t index) {
     return factory->undefined_value();
   }
 
-  Handle<Object> char_at = GetProperty(
-      isolate, isolate->js_builtins_object(), factory->char_at_string());
+  Handle<Object> char_at = Object::GetProperty(
+      isolate->js_builtins_object(), factory->char_at_string());
   if (!char_at->IsJSFunction()) {
     return factory->undefined_value();
   }