[Bug target/80782] Configure options to use llvm/clang assembler on Mac

["rjvbertin at gmail dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80782

--- Comment #7 from René J.V. Bertin <rjvbertin at gmail dot com> ---
(In reply to Jonathan Wakely from comment #6)

> I assume something like --with-as=llvm-as doesn't work.

Nope.

> It would require
> configure to know how to detect the llvm assembler and know how to invoke it
> correctly.

The latter is the bigger problem, and not for configure to solve but for the
compiler driver.

> If Apple's gas already understands the llvm assembler options then
> leveraging that seems sensible. So all that would be needed is a way to
> configure GCC to always use -Wa,-q

Indeed. As I said in my previous comment:
"It would be useful if GCC could be configured to include platform-specific
arguments for the default assembler, in this case `-q`."

I presume that --with-as="/path/to/as -q" would try to execute an executable
called "as -q" but haven't tried.