fix: bug at Name.beq

This PR fixes a bug at `Name.beq` reported by gasstationcodemanager@gmail.com

src/runtime/object.cpp

@@ -2649,7 +2649,7 @@ extern "C" LEAN_EXPORT uint8 lean_name_eq(b_lean_obj_arg n1, b_lean_obj_arg n2)
             if (!lean_string_eq(lean_ctor_get(n1, 1), lean_ctor_get(n2, 1)))
                 return false;
         } else {
-            if (!lean_nat_eq(lean_ctor_get(n1, 1), lean_ctor_get(n1, 1)))
+            if (!lean_nat_eq(lean_ctor_get(n1, 1), lean_ctor_get(n2, 1)))
                 return false;
         }
         n1 = lean_ctor_get(n1, 0);

tests/lean/run/name_eq_bug.lean

@@ -0,0 +1,10 @@
+open Lean
+-- Two DIFFERENT numbers >= 2^64
+def n1 := Name.num .anonymous (2^64) -- 18446744073709551616
+def n2 := Name.num .anonymous (2^64 + 1) -- 18446744073709551617
+-- These are clearly different
+#guard (2^64 : Nat) ≠ (2^64 + 1 : Nat) -- passes
+
+/-- info: false -/
+#guard_msgs in
+#eval Name.beq n1 n2