[TTI] Don't drop VP intrinsic args when delegating to non-vp equivalent (#147677)
Previously we only carried the type arguments which caused value-based
costs to be inadvertantly changed into type-based costs.
I'm just using vp.is.fpclass as an example intrinsic for now since the
type based cost seems to differ from the value based cost, and most
normal intrinsics e.g. min/max have the same value + type based cost.
We still need to handle the cost properly for is.fpclass in a second
patch.
This is needed for an upcoming patch to handle the cost of
llvm.experimental.vp.reverse which suffers from the same problem.