[Chapel Merge] Remove ascii opt from 18323

Branch: refs/heads/main
Revision: 65f3807
Author: mppf
Log Message:

Merge pull request #18351 from mppf/follow-18346

Remove ascii opt from 18323

Follow-up to #18323 and #18346.

This PR removes for now a tiny optimization for ascii strings that was added in #18323.

The removed optimization causes timeouts for knucleotide-strings when compiled with checks / without --fast.

The reason for that is that string.isASCII can run countNumCodepoints when boundsChecking is enabled.

Trivial and not reviewed.