Add test whether "-stdlib=libc++" needs to be added to the command line.
Add test whether "-stdlib=libc++" needs to be added to the command line.

For clang++ on Mac OS X.

tuscland/liblo,kneitinger/liblo,umlaeute/liblo,radarsat1/liblo,island-org/liblo,kneitinger/liblo,fsateler/liblo,fsateler/liblo,tuscland/liblo,johne53/MB3Liblo,island-org/liblo,umlaeute/liblo,kneitinger/liblo,island-org/liblo,radarsat1/liblo,johne53/MB3Liblo,tuscland/liblo,umlaeute/liblo,fsateler/liblo,radarsat1/liblo,johne53/MB3Liblo,johne53/MB3Liblo