Fix false positive unreachable with Any in equality comparison

mypy/checker.py

@@ -7072,6 +7072,8 @@ def refine_away_none_in_comparison(
         non_optional_types = []
         for i in chain_indices:
             typ = operand_types[i]
+            if isinstance(get_proper_type(typ), AnyType):
+                continue
             if not is_overlapping_none(typ):
                 non_optional_types.append(typ)
 

test-data/unit/check-unreachable-code.test

@@ -1650,3 +1650,10 @@ def x() -> None:
 main:4: error: Statement is unreachable
         if 5:
         ^~~~~
+
+[case testNoFalseUnreachableWithAnyEqualityNarrowing]
+# flags: --warn-unreachable
+from typing import Any, Optional
+def main(contents: Any, commit: Optional[str]) -> None:
+    if contents.get("commit") == commit:
+        reveal_type(commit)  # N: Revealed type is "builtins.str | None"