[RISCV] Add fixed length vector patterns for vfwmaccbf16.vv (#108204)

This adds VL patterns for vfwmaccbf16.vv so that we can handle fixed
length vectors.

It does this by teaching combineOp_VLToVWOp_VL to emit
RISCVISD::VFWMADD_VL for bf16. The change in getOrCreateExtendedOp is
needed because getNarrowType is based off of the bitwidth so returns
f16. We need to explicitly check for bf16.

Note that the .vf patterns don't work yet, since the build_vector splat
gets lowered to a (vmv_v_x_vl (fmv_x_anyexth x)) instead of a vfmv.v.f,
which SplatFP doesn't pick up, see #106637.

0 files changed, 0 insertions, 0 deletions