In commit v3.0.0-rc1~551^2~1 (Check*CompilerFlag: make C and CXX modules
share most error patterns, 2013-08-08) a pattern containing a ';' was
moved out of a ""-quoted argument and into a variable. CMake flattens
the containing list and breaks the pattern. Use a '.' to match ';'.
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.