This patch adds lld support for:
- Dynamic R_AARCH64_AUTH_* relocations (including RELR compressed AUTH relocations) as described here: https://github.com/ARM-software/abi-aa/blob/main/pauthabielf64/pauthabielf64.rst#auth-variant-dynamic-relocations
- .note.AARCH64-PAUTH-ABI-tag section as defined here https://github.com/ARM-software/abi-aa/blob/main/pauthabielf64/pauthabielf64.rst#elf-marking
Co-authored-by: Peter Collingbourne <peter@pcc.me.uk>
nopack-relative-auth-relocs is untested.