Changes in this patch:
- Minor changes to the LowerVECREDUCE_SEQ_FADD function added by @cameron.mcinally
to also work for scalable types
- Added TableGen patterns for FP reductions with unpacked types (nxv2f16, nxv4f16 & nxv2f32)
- Asserts added to expandFMINNUM_FMAXNUM & expandVecReduceSeq for scalable types
Reviewed By: cameron.mcinally
Differential Revision: https://reviews.llvm.org/D93050
Kerry McLaughlin