mathlib

132b0fe9 - fix(scripts): make lint-style.* work on macos and windows (#6047)

fix(scripts): make lint-style.* work on macos and windows (#6047) Make lint-style.sh use a POSIX-portable way of checking for executable bits, and make it always open files as UTF-8. Also makes CI run the sanity checks across all 3 OSes to ensure this stays working.