[LLVM-122] BTI and PAC support in LLD Implementation now working, have written BTI tests, next step is finishing off PAC tests.

[Misc] Helped out debugging an asm-goto problem on ARM targets.

Investigated a GNU ld LMA overlap when VMA and LMA got out of sync.

Helped out with CMSIS use of ld scripts when using a fast-model, needed to get LMA == VMA for program header covering BSS.