add newline to satisfy ModuleNotices test
Merge topic 'cxx-flags' into next

2840e29 add newline to satisfy ModuleNotices test
Check*CompilerFlag: make C and CXX modules share most error patterns (#14339)

This simplifies maintenance as most patterns will be for both modules and may
be added at a central place.

While at it add error patterns for XL and BCC.
Merge topic 'cxx-flags' into next

6f3ebfe Check*CompilerFlag: make C and CXX modules share most error patterns (#14339)