Fix pipeline operator when called in a loop

The previous implementation would mutate the expr args, but the expr is shared between the loop iterations, so the second iteration would use the mutated args from the first iteration.

Now, it creates a new expr for each iteration.

Author: MatheusRich

src/lit/interpreter.cr

@@ -238,8 +238,10 @@ module Lit
 
     def visit_binary_expr(expr) : Value
       if expr.operator.type.pipe_greater?
-        expr.right.as(Expr::Call).arguments.unshift(expr.left)
-        return evaluate(expr.right)
+        right = expr.right.as(Expr::Call)
+        call = Expr::Call.new(right.callee, right.paren, [expr.left] + right.arguments)
+
+        return evaluate(call)
       end
 
       left = evaluate(expr.left)