Add AVR-GCC 13.2.0 formula

[davidstritzl]

The new formula is based on the formula for AVR-GCC 12.2.0. The URL, mirror, checksum and patches by the Darwin GCC maintainer were updated to GCC 13. The compile test is kept the same as the produced hex file seems to be unchanged. Testing was done on macOS 14.1 (AArch64).

Furthermore, a new entry for AVR-GCC 13.2.0 was added to the README.

[davidstritzl]

Signed commits and rebased onto the latest main.

It should also be noted that I have been succesfully using this formula to target multiple different ATmega microcontrollers for the past few months.

[ladislas]

thanks for the PR! can you check the errors and fix the style? :)

[davidstritzl]

The style violations should be fixed now.

I also noticed I wasn't building against the latest Xcode/CommandLineTools. With Xcode 15.3, I got some compilation errors for libc++ (see this GCC issue). I included the patches from the Homebrew Core GCC 13 formula to fix the compilation.

[ladislas]

@davidstritzl there are still some issues

[davidstritzl]

That's too bad. I think I have another machine capable of macOS 12 around. I'll have to get it up to speed, though, so it will have to wait until the weekend.

[davidstritzl]

I tested the formula on both, AArch64 and x86_64, variants of macOS 12. It seems the patch application only failed on the latter, so I disabled this patch for non-AArch64 systems.

Also, I rebased the formula on the lastest main to fix a merge conflict in the README.

[ladislas]

Thank you very much!