[llvm] [PowerPC] Add dense math bfloat16 floating-point outer-product accumulate to DMR instructions (PR #132318)

[Maryam Moghadas via llvm-commits]

maryammo wrote:

Since the next PR to add dense math half-precision FP calculation instructions depends on this one, I close this to create a branch and be able to post dependent PR's.  (https://llvm.org/docs/GitHub.html#branches)

https://github.com/llvm/llvm-project/pull/132318