This patch includes an empty heart into BRL-CAD by adding the src/librt/primitives/hrt/hrt.c file, editing the rt_functab[] array in src/librt/primitives/table.c and obviously the src/librt/CMakelists.txt.It applied cleanly and build succeeds. when tested on mged and archer with the in command, the respective functions print the "Sorry, This function is not implemented yet!\n" sentence.
Fixed the failing table.c file
Applied as patch 56642