Code Coverage (#82)

code coverage:  generate code coverage reports

* Add instrumentation flags to rocshmem target when adding -DBUILD_CODE_COVERAGE cmake flag
* Add helper script to build all subprojects and generate code coverage reports
* Update README with code coverage instructions

[ROCm/rocshmem commit: 474112d03c]

projects/rocshmem/scripts/build_configs/ro_ipc

@@ -36,6 +36,7 @@ fi
 src_path=$(dirname "$(realpath $0)")/../../
 
 cmake \
+    -DBUILD_CODE_COVERAGE=${CODE_COV:-OFF} \
     -DCMAKE_BUILD_TYPE=Release \
     -DCMAKE_INSTALL_PREFIX=$install_path \
     -DCMAKE_VERBOSE_MAKEFILE=OFF \