fix implementation (fixing a bug surfaced by Python 🙏)

Author: MangelMaxime

src/Fable.Transforms/FableTransforms.fs

@@ -242,9 +242,19 @@ let canInlineArg (com: Compiler) identName value body =
     | _ ->
         let refCount = countReferencesUntil 2 identName body
 
+        // Inlining a plain identifier reference is always safe (it's just a rename),
+        // regardless of whether the ident is captured in a closure.
+        let isIdentValue =
+            match value with
+            | IdentExpr _ -> true
+            | _ -> false
+
         // Don't inline even side-effect-free values when they're captured in a closure (e.g. object expression
         // getter): inlining would create a new value on each closure invocation instead of sharing one instance.
-        (refCount <= 1 && not (canHaveSideEffects com value) && not (isIdentCaptured identName body))
+        // Exception: plain ident values are always safe to inline (they don't create new objects).
+        (refCount <= 1
+         && not (canHaveSideEffects com value)
+         && (isIdentValue || not (isIdentCaptured identName body)))
         // If it can have side effects, make sure is at least referenced once so the expression is not erased
         || (refCount = 1
             && noSideEffectBeforeIdent identName body