Sema/arith.zig: Fixing more typos from #23177.

This is a complementary PR to #23487 (I had only found one typo before).

Now I've looked at the whole `arith.zig` file, trying to find other potential problems.

Discussion about these changes:
https://github.com/ziglang/zig/pull/23177#discussion_r1997957095
4fc783670aMun Maks committed on 4/9/2025, 11:53:11 AM· committed by Matthew Luggparent79a620d
1 file changedLine totals unavailable