[llvm] [llvm][arm] add T1 and T2 assembly options for vlldm and vlstm (PR #83116)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

@tmatheson-arm @sivan-shani This is causing failures on EXPENSIVE_CHECKS builds - please can you take a look?
https://lab.llvm.org/buildbot/#/builders/16/builds/61858


https://github.com/llvm/llvm-project/pull/83116