The FMulAdd (CombinedVectorize) transformation in transformNodes() marks
an FMul child entry with zero cost, assuming it is fully absorbed into
the fmuladd intrinsic. However, when any FMul scalar has multiple uses
(e.g., also stored separately), the FMul must survive as a separate
node.
Reviewers: hiraditya, RKSimon, bababuck
Pull Request: https://github.com/llvm/llvm-project/pull/189692
c6669c4993