perf: add frozenset fast-path for comparator type dispatch

Use O(1) frozenset membership test with type identity before falling
through to isinstance MRO traversal. Backported from codeflash-python.

codeflash/verification/comparator.py

@@ -74,6 +74,27 @@ _DICT_KEYS_TYPE = type({}.keys())
 _DICT_VALUES_TYPE = type({}.values())
 _DICT_ITEMS_TYPE = type({}.items())
 
+_IDENTITY_EQ_TYPES: frozenset[type[Any]] = frozenset(
+    {
+        int,
+        bool,
+        complex,
+        type(None),
+        type(Ellipsis),
+        decimal.Decimal,
+        set,
+        bytes,
+        bytearray,
+        memoryview,
+        frozenset,
+        type,
+        range,
+        slice,
+        OrderedDict,
+        types.GenericAlias,
+    }
+)
+
 _EQUALITY_TYPES = (
     int,
     bool,
@@ -184,12 +205,18 @@ def comparator(orig: Any, new: Any, superset_obj: bool = False) -> bool:
 
             return False
 
-        if type(orig) is not type(new):
-            type_obj = type(orig)
-            new_type_obj = type(new)
+        orig_type = type(orig)
+        if orig_type is not type(new):
             # distinct type objects are created at runtime, even if the class code is exactly the same, so we can only compare the names
-            if type_obj.__name__ != new_type_obj.__name__ or type_obj.__qualname__ != new_type_obj.__qualname__:
+            if orig_type.__name__ != type(new).__name__ or orig_type.__qualname__ != type(new).__qualname__:
                 return False
+        # Fast-path: O(1) frozenset lookup for common types (avoids isinstance MRO traversal)
+        if orig_type in _IDENTITY_EQ_TYPES:
+            return orig == new
+        if orig_type is float:
+            if math.isnan(orig) and math.isnan(new):
+                return True
+            return math.isclose(orig, new)
         if isinstance(orig, (list, tuple, deque, ChainMap)):
             if len(orig) != len(new):
                 return False
@@ -204,12 +231,9 @@ def comparator(orig: Any, new: Any, superset_obj: bool = False) -> bool:
                 return _normalize_temp_path(orig) == _normalize_temp_path(new)
             return False
 
+        # enum.Enum subclasses and UnionType fall through from the frozenset fast-path
         if isinstance(orig, _EQUALITY_TYPES):
             return orig == new
-        if isinstance(orig, float):
-            if math.isnan(orig) and math.isnan(new):
-                return True
-            return math.isclose(orig, new)
 
         # Handle weak references (e.g., found in torch.nn.LSTM/GRU modules)
         if isinstance(orig, weakref.ref):