[lld][AArch64][ELF][PAC] Support AUTH relocations and AUTH ELF marking (#72714)

This patch adds lld support for:

- Dynamic R_AARCH64_AUTH_* relocations (without 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



Depends on #72713 and #85231

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Co-authored-by: Peter Collingbourne <peter@pcc.me.uk>
Co-authored-by: Fangrui Song <i@maskray.me>