[Issue 11229] std.string.toLower is slow

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=11229

--- Comment #12 from Jon Degenhardt <jrdemail2000-dl...@yahoo.com> ---
Ascii check optimization for asLowerCase and asUpperCase in this commit:
https://github.com/dlang/phobos/commit/f257e8330e5babbf5c74325dc32a2886bd181f02

--