[pytrees] Allow tree_map_only to support predicate function as filter (#119974)
In many places in the code we use `tree_map_only((SymInt, SymBool, SymFloat), foo)` but with nested ints, it is possible to have SymInts that are non-symbolic, so we may want to do something like `tree_map_only(is_symbolic, foo)` instead.
Alternative: wrap nested int SymNodes with something other than SymInt.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/119974
Approved by: https://github.com/zou3519
ghstack dependencies: #119661
