My previous RFC[1] tried to add recordmcount as the mcount subcommand
of objtool. As a necessary first step that required enabling building
of objtool for more than the x86 architecture.
Some folks have been working on enabling objtool checking functionality
for arm64. Rather than repeat that work here I aim to show a minimal
set which ensures that objtool builds for any architecture. This
will allow for not only building the check and ORC subcommands
but also incorporating more subcommands -- such as recordmcount.