100% behavior tests passing for the aarch64 backend

[andrewrk]

Issue close criteria:

$ stage3/bin/zig test ../test/behavior.zig -target aarch64-linux --test-cmd qemu-aarch64 --test-cmd-bin
...
1832 passed; 111 skipped; 0 failed.
$ stage3/bin/zig test ../test/behavior.zig -target aarch64-linux --test-cmd qemu-aarch64 --test-cmd-bin -fno-llvm -fno-lld
Segmentation fault (core dumped)

When the second command has a number passing >= to the first command, this issue can be closed.

Related:

• 100% behavior tests passing for the x86_64 backend #22256

[jacobly0]

Current progress is 1559/1964 (79%), with the caveat that safety is not yet enabled and should be enabled before closing this issue.