Fix scalar overload name constructed by ReplaceWithVeclib.cpp (#111095)
ReplaceWithVeclib.cpp would construct overload name using all the
arguments in the intrinsic, but overloads should only be constructed
from arguments for which isVectorIntrinsicWithOverloadTypeAtArg returns
true, including the return type first (index -1).
Additionally,
- skip when `Intrinsic::not_intrinsic`, otherwise
`isVectorIntrinsicWithOverloadTypeAtArg` asserts for some
IntrinsicCalls.
Unblocks translation for pow and atan2 intrinsics.
Fixes #111093