[AMDGPU] Precommit test for issue in amdgpu-rewrite-agpr-copy-mfma, (#168609)
which reassigns scale operand in vgpr_32 register to agpr_32, not
permitted by instruction format. Reduced from ck.
---------
Co-authored-by: Matt Arsenault <arsenm2@gmail.com>
Co-authored-by: theRonShark <ron.lieberman@amd.com>