Shrink AOT snapshot size and memory usage.

runtime/vm/raw_object.cc

Index: runtime/vm/raw_object.cc
diff --git a/runtime/vm/raw_object.cc b/runtime/vm/raw_object.cc
index 2c2650fda9e8dfc10fb7c30d0447ab718ff779c3..991b2e0f254940cf0e0606fa3fb0de4f63e259d9 100644
--- a/runtime/vm/raw_object.cc
+++ b/runtime/vm/raw_object.cc
@@ -442,6 +442,9 @@ intptr_t RawFunction::VisitFunctionPointers(RawFunction* raw_obj,
     visitor->VisitPointers(raw_obj->from(), raw_obj->to());
     return Function::InstanceSize();
   }
+#if defined(DART_PRECOMPILED_RUNTIME)
+  UNREACHABLE();
+#else
   visitor->VisitPointers(raw_obj->from(), raw_obj->to_no_code());
 
   if (ShouldVisitCode(raw_obj->ptr()->code_)) {
@@ -457,6 +460,7 @@ intptr_t RawFunction::VisitFunctionPointers(RawFunction* raw_obj,
   } else {
     visitor->add_skipped_code_function(raw_obj);
   }
+#endif
   return Function::InstanceSize();
 }