#24452 The change prevents inlining implicitly undefined variables to void 0, which causes let a; a * 0 to never be inlined. It also blocks the inlining of (void 0 * 2) if it's implemented in the future.

I assumed void 0 * 2 is transformed to 0/0 (NaN). But I guess it will still be console.log(0/0) if that's implemented, as let a; console.log((a + "").length); is transformed to console.log(9);.

Originally posted by @sapphi-red in #24452 (comment)