[5.9.0] Update macro help in driver and diagnostics#67887

Merged

bnbarham merged 2 commits intoswiftlang:release/5.9.0from

bnbarham:5.9.0-update-macro-help

Aug 12, 2023

Commits on Aug 11, 2023

[Macros] Update help message for '-load-plugin-executable'

rintaro
authored and
bnbarham
committed
[Diagnostics] Reduce missing external macro diagnostic
bnbarham
committed