Make add_coverage_targets a true function.
Make add_coverage_targets a true function.

So it can be called multiple times.

shurikasa/CMake,biddisco/CMake,ptoharia/CMake,ptoharia/CMake,shurikasa/CMake,ptoharia/CMake,biddisco/CMake,biddisco/CMake,biddisco/CMake,shurikasa/CMake,ptoharia/CMake,shurikasa/CMake