[bounty] [pr] index validation with z3 (#9981)

* index validation with z3

* Change comment

* toposort -> toposort()

---------

Co-authored-by: George Hotz <72895+geohot@users.noreply.github.com>

test/test_symbolic_jit.py

@@ -2,9 +2,18 @@ import unittest
 
 from test.helpers import assert_jit_cache_len
 from tinygrad import Variable, Tensor, TinyJit
+from tinygrad.helpers import Context
 import numpy as np
 
 class TestSymbolicJit(unittest.TestCase):
+  def setUp(self):
+    # A lot of these test are out of bounds, so we ignore the bounds check
+    self.context = Context(IGNORE_OOB=1)
+    self.context.__enter__()
+
+  def tearDown(self):
+    self.context.__exit__(None, None, None)
+
   def test_plus1(self):
     def f(a): return (a+1).realize()
     jf = TinyJit(f)
@@ -290,4 +299,4 @@ class TestSymbolicJit(unittest.TestCase):
         np.testing.assert_allclose(symbolic, expected, atol=1e-6, rtol=1e-6)
 
 if __name__ == '__main__':
-  unittest.main()
+  unittest.main()