Updates to run coverage with clang by default instead of gcc

norvellrequested to merge
float-1537-make-clang-the-default-compiler-in-makefile-and-cmakelists-txt-clang-coverage into float-1537-make-clang-the-default-compiler-in-makefile-and-cmakelists-txt

Updates to run coverage with clang by default instead of gcc

Merge request reports