Move legacy range constraint calculator to executorch to unblock pytorch CI (#2925)

Summary:
Pull Request resolved: #2925

To unblock: D55730289

Reviewed By: angelayi

Differential Revision: D55892116

fbshipit-source-id: 657a3f580871ed24c3095deccc8111d0f3002fa2

Author: tugsbayasgalan

exir/program/_program.py

@@ -48,7 +48,6 @@
     unsafe_remove_auto_functionalized_pass,
 )
 from torch.export.exported_program import (
-    _get_updated_range_constraints,
     ConstantArgument,
     ExportGraphSignature,
     InputKind,
@@ -64,6 +63,39 @@
 Val = Any
 
 
+def _get_updated_range_constraints(gm):
+    def get_shape_env(gm):
+        vals = [
+            node.meta["val"]
+            for node in gm.graph.nodes
+            if node.meta.get("val", None) is not None
+        ]
+        from torch._guards import detect_fake_mode  # type: ignore[21]
+
+        fake_mode = detect_fake_mode(vals)
+        if fake_mode is not None:
+            return fake_mode.shape_env
+        for v in vals:
+            if isinstance(v, torch.SymInt):
+                return v.node.shape_env
+
+    shape_env = get_shape_env(gm)
+    if shape_env is None:
+        return {}
+    range_constraints = {
+        k: v
+        for k, v in shape_env.var_to_range.items()
+        if k not in shape_env.replacements
+    }
+    # Only when we have an unbacked symint, and it's used as constructor inputs,
+    # runtime_var_to_range will make a difference compated to var_to_range.
+    # e.g. [2, oo) -> [0, oo)
+    for k, v in shape_env.var_to_range.items():
+        if k not in shape_env.replacements:
+            range_constraints[k] = v
+    return range_constraints
+
+
 def _get_updated_graph_signature(
     old_signature: ExportGraphSignature,
     new_gm: torch.fx.GraphModule,