[llvm] [RISCV][TypePromotion] Dont generate truncs if PromotedType is greater than Source Type (PR #86941)

[Sudharsan Veeravalli via llvm-commits]

svs-quic wrote:

Could someone please merge this if everyone is okay with the change? I don't have commit access.

https://github.com/llvm/llvm-project/pull/86941