Force use of C++ linker for app tests.
Force use of C++ linker for app tests.

surround-io/oclgrind,surround-io/oclgrind,bitfusionio/Oclgrind,bitfusionio/Oclgrind,bitfusionio/Oclgrind,mpflanzer/Oclgrind,mpflanzer/Oclgrind,mpflanzer/Oclgrind,surround-io/oclgrind,mpflanzer/Oclgrind,surround-io/oclgrind,bitfusionio/Oclgrind