add support for Darwin on ARM

DS2 support for Mach on ARM is not currently implemented.

The build GHA fails the macos build because the [macos-latest runner](https://docs.github.com/en/actions/using-github-hosted-runners/about-github-hosted-runners/about-github-hosted-runners#supported-runners-and-hardware-resources) (macos-14) runs on an M1 CPU.

```
cmake -B /Users/runner/work/ds2/ds2/BinaryCache/ds2 -C /Users/runner/work/ds2/ds2/cmake/caches/ClangWarnings.cmake -D CMAKE_BUILD_TYPE=Release -G Ninja -S /Users/runner/work/ds2/ds2
shell: /bin/bash -e {0}
loading initial cache file /Users/runner/work/ds2/ds2/cmake/caches/ClangWarnings.cmake
-- The C compiler identification is AppleClang 15.0.0.15000040
-- The CXX compiler identification is AppleClang 15.0.0.15000040
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /Applications/Xcode_15.0.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /Applications/Xcode_15.0.1.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
CMake Deprecation Warning at Tools/JSObjects/CMakeLists.txt:11 (cmake_minimum_required):
Compatibility with CMake < [3](https://github.com/compnerd/ds2/actions/runs/9876583186/job/27276060690?pr=86#step:4:3).5 will be removed from a future version of
CMake.

Update the VERSION argument value or use a ... suffix to tell
CMake that the project does not need compatibility with older versions.

-- Found BISON: /usr/bin/bison (found version "2.3")
-- Found FLEX: /usr/bin/flex (found version "2.6.[4](https://github.com/compnerd/ds2/actions/runs/9876583186/job/27276060690?pr=86#step:4:5)")
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE
-- Configuring done (4.8s)
CMake Error at CMakeLists.txt:321 (target_sources):
Cannot find source file:

Sources/Host/Darwin/ARM/MachARM.cpp

Tried extensions .c .C .c++ .cc .cpp .cxx .cu .mpp .m .M .mm .ixx .cppm
.ccm .cxxm .c++m .h .hh .h++ .hm .hpp .hxx .in .txx .f .F .for .f77 .f90
.f9[5](https://github.com/compnerd/ds2/actions/runs/9876583186/job/27276060690?pr=86#step:4:6) .f03 .hip .ispc

CMake Generate step failed. Build files cannot be regenerated correctly.
-- Generating done (0.0s)
Error: Process completed with exit code 1.
```