[llvm] DAG: Replace legal type check in EmitCopyFromReg (PR #177788)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

Sorry - I hadn't been following this as I thought it was dependent on a SystemZ fix - is the plan to fix SystemZ i128 handling as a followup and then to drop your workaround?

https://github.com/llvm/llvm-project/pull/177788