UOp.variable (#7010)

* UOp.variable [pr]

* fix tests

* clean

* improve name rendering

* last bug

extra/optimization/helpers.py

@@ -1,12 +1,13 @@
 # stuff needed to unpack a kernel
 from typing import Tuple
 from extra.ops import LazyOp, TernaryOps, BinaryOps, UnaryOps, ReduceOps, BufferOps, MemBuffer, ConstBuffer, MetaOps
+from tinygrad import Variable
 from tinygrad.codegen.kernel import Opt, OptOps
 from tinygrad.ops import UOp, UOps, KernelInfo
 from tinygrad.dtype import dtypes, PtrDType
 from tinygrad.shape.shapetracker import ShapeTracker
 from tinygrad.shape.view import View
-from tinygrad.shape.symbolic import Variable, NumNode
+from tinygrad.shape.symbolic import NumNode
 inf, nan = float('inf'), float('nan')
 
 # kernel unpacker

extra/optimization/test_beam_search.py

@@ -2,8 +2,7 @@ import unittest
 import numpy as np
 
 from tinygrad.helpers import BEAM, Timing, CI
-from tinygrad.shape.symbolic import Variable
-from tinygrad.tensor import Tensor
+from tinygrad import Variable, Tensor
 from tinygrad.nn import Conv2d
 
 def rand(*shape):