698cfd0811 docs: Mention lint-locale-dependence.sh in developer-notes.md (practicalswift)
0a4ea2f458 build: Add linter for checking accidental locale dependence (practicalswift)
Pull request description:
This linter will check for code accidentally introducing locale dependencies.
Unnecessary locale dependence can cause bugs that are very tricky to isolate and fix. We should avoid using locale dependent functions if possible.
Context: https://github.com/bitcoin/bitcoin/pull/12881#issuecomment-378564722
Example output:
```
$ contrib/devtools/lint-locale-dependence.sh
The locale dependent function tolower(...) appears to be used:
src/init.cpp: if (s[0] == '0' && std::tolower(s[1]) == 'x') {
Unnecessary locale dependence can cause bugs that are very
tricky to isolate and fix. Please avoid using locale dependent
functions if possible.
Advice not applicable in this specific case? Add an exception
by updating the ignore list in contrib/devtools/lint-locale-dependence.sh
```
**Note to reviewers:** What is the most appropriate `LOCALE_DEPENDENT_FUNCTIONS` function list? What should be added or removed?
Tree-SHA512: 14e448828804bb02bf59070647e38b52fce120c700c903a4a8472769a2cee5dd529bd3fc182386993cb8720482cf4250b63a0a477db61b941ae4babe5c65025f
