Multiple replacements based on character sets in a single pass. Useful
for string sanitation. Follows existing `multiReplace` semantics.
Note: initially copied the substring version logic with a `while` and a
named block break, but Godbolt showed it had produced slightly larger
assembly using higher registers than the final version.
- [x] Tests
- [x] changelog.md
(cherry picked from commit 909f3b8b79)