[cmake-developers] CMAKE_C_COMPILER_ARG# not documented?

[Robert Dailey]

I can't remember where I heard about these CMake variables, but in one
of my toolchain files I do this:

set( CMAKE_C_COMPILER_ARG1 -m32 )
set( CMAKE_CXX_COMPILER_ARG1 -m32 )

On the [cmake variables][1] page, these are not documented. I expected
an entry somewhere like `CMAKE_<LANG>_COMPILER_ARG<#>` but there isn't
one. Are these documented? If so, where? If not, I'll create an issue
on the gitlab project page to make sure that gets done at some point.
I would offer to do it but I'm not too sure what the variables do
myself, nor am I sure what the upper limit for ARG is.

[1]: https://cmake.org/cmake/help/latest/manual/cmake-variables.7.html