This patch replaces FixedVectorType by VectorType in getIntrinsicInstrCost
in BasicTTIImpl.h. It re-arranges the scalable type test earlier return
and add tests for scalable types.
This patch is the first series of patches to fix getIntrinsicInstrCost for scalable
Patches to fix the intrinsics masked gather and masked scatter, vector reduce
and fshl/fshr will be in upcoming patches.
Depends on D91532