Rollup merge of #139893 - reddevilmidzy:add-test, r=SparrowLii

Add test for issue 125668

closes: #125668

The issue stemmed from improper handling of const {} blocks used in array length expressions. As of rustc 1.80.0-nightly (804421dff 2024-06-07), this ICE no longer occurs and the code compiles successfully 😀

Author: matthiaskrgr