Llama 8b Perplexity and Accuracy test Failing

[vivekkhandelwal1]

The Llama-8b-fp16 perplexity and accuracy tests have been marked xfail here: #2694.

This issue is to track these xfail tests and the corresponding fix for the same.

[vivekkhandelwal1]

The perplexity tests are fixed by #2710.

[vivekkhandelwal1]

For reproducing the failure for accuracy test, IRPA can be downloaded from here.