Question about the evaluation order of built-in functions

As mentioned in [ir-breaking-changes](https://docs.soliditylang.org/en/latest/ir-breaking-changes.html#), **addmod** is evaluated from right to left in the legacy codegen, but from left to right in the IR-based codegen. I would like to understand the reason behind this difference. What determines the evaluation order of arguments, and is there a specific part of the source code that defines this behavior?

Start with the ir-breaking-changes documentation section linked in the issue, then trace addmod argument evaluation through the legacy and IR-based codegen paths. Identify what determines each order and document the relevant source locations and rationale. Done means the difference and its source are clearly explained.

Written by the indexing model from the issue text.