Add macOS Arm support

[chrismaltby]

I'm working on updating GB Studio to support M1/M2/M3 Macs natively, noticed that the gbdk-2020 main repo fetches sdcc builds from this repo so just wanted to add Mac arm64 support (I can make a PR into gbdk-2020 main repo if you're happy with this change)

• Github actions added arm64 support with the macos-14 runners so I've added that to the matrix https://github.blog/changelog/2024-01-30-github-actions-macos-14-sonoma-is-now-available/
• Homebrew on arm64 installs to a different directory by default (/opt/homebrew) so I've had to set LDFLAGS and CPPFLAGS just for macos-14
• I was getting link problems for libisl, libzstd, sounds like you had similar on Mac x64 based on the comments but the fix of using the official cc1 build I don't think could work here as I couldn't find an official Mac arm build of cc1. Seems like clang will always prefer to use dynamic libraries when available, to fix this I copied all the static libraries to a different folder and set LDFLAGS to point to that instead. Not sure if that's a good idea or not but seemed to work. I left the Mac x64 build fix as is, but if you're happy with this I could submit another PR to do a similar fix for that build
• I noticed the Mac x64 build was timing out, it turns out homebrew dropped support for prebuilt boost libraries on macos-11 at some point very recently so it was trying to compile from source adding 30 minutes to the build time for Mac x64 which would 50/50 chance timeout. The fix was to update to using macos-13 for the x64 build which was the last macOS that GitHub actions uses Intel based runners for
• The x64 update to using macos-13 then introduced an issue where homebrew tried to install python3 after completing the brew install step and was clashing with a version already installed by the os, the fix for this was to set the environment variable HOMEBREW_NO_INSTALLED_DEPENDENTS_CHECK=1

You can see the result of running this updated action here https://github.com/chrismaltby/gbdk-2020-sdcc/actions/ I've rebuilt GBDK-2020 using the SDCC build from running these actions and all seems to be working, I've also tested this running builds from GB Studio.

[bbbbbr]

This is amazing! Appreciate you figuring out how to get it working and PRing the support.

Does updating the intel Mac runner to macos-13 from macos-11 will have any impact on OS compatibility. I don't know enough about the platform to understand how the export MACOSX_DEPLOYMENT_TARGET=10.10 setting interacts with potential changes in target OS support in the toolchain on 13.

Although if the older runners often aren't able to complete their build anymore due to the homebrew changes, then maybe my question is kind of a moot point. :sweat_smile:

Let's leave the Intel Mac cc1 build fix as is for now.

[chrismaltby]

Happy to help :-)

I forgot to mention yes I'd tested this on an Intel Mac running 10.14.5 and it's still working as expected. Not really sure how the MACOSX_DEPLOYMENT_TARGET env variable changes things myself either but looks like moving from macOS 11 to macOS 13 didn't break support for macOS 10.x from what I can see

[bbbbbr]

Perfect, thanks! Merging :)