explicit dynamic shapes maps namings (#172405) (#173017)

Summary:
- this map only used for backed.
var_to_val -> backed_var_to_val

-  this map only used for real tensor prop
unbacked_var_to_val -> real_tensor_prop_unbacked_vals

X-link: pytorch/pytorch#173017
Approved by: https://github.com/aorenste, https://github.com/bobrenjc93

Reviewed By: aorenste

Differential Revision: D91176254

fbshipit-source-id: 6b332548db5a0854fd0950639853c4e6e6a7522c

Author: laithsakka

userbenchmark/dynamo/dynamobench/_dynamo/utils.py

@@ -3497,12 +3497,12 @@ def get_concrete_sizes_from_symints(
     pattern = r"\(s(\d+)\)"
     assert fake_mode.shape_env is not None
     shape_env = fake_mode.shape_env
-    var_to_val = shape_env.var_to_val
+    backed_var_to_val = shape_env.backed_var_to_val
 
     def replace_sym(match: Any) -> str:
         sym_name = f"s{match.group(1)}"
         val = next(
-            (v for k, v in var_to_val.items() if k.name == sym_name),
+            (v for k, v in backed_var_to_val.items() if k.name == sym_name),
             None,
         )
         if isinstance(val, (int, Integer)):