Re-land "[AArch64] Add FEAT_PAuthLR assembler support" (#75947)

This reverts commit 199a0f9f5aaf72ff856f68e3bb708e783252af17.
Fixed the left-shift of signed integer which was causing UB.

GitOrigin-RevId: 192f720178732885ec86062b92daf3d562aea427
15 files changed