[llvm] Convert copy to r-value reference. (PR #85606)

[Malay Sanghi via llvm-commits]

MalaySanghiIntel wrote:

@phoebewang 
Please review this change. 

The original author seems to have referred code in a different file which has the same issue. I can create a separate PR for that.

https://github.com/llvm/llvm-project/pull/85606