[1/7][Clang][RISCV] Remove default tail-undisturbed for vector reduction intrinsics

The destination parameter is removed for non-policy unmasked intrinsics,
they are now tail agnostic. The non-policy masked intrinsics are tail
agnostic and masked undisturbed, just like normal instructions like
vadd.

This is the 1st commit of a patch-set that aims to remove the
`IsPrototypeDefaultTU` special case for the rvv-intrinsics.

The patch-set work towards the simplification proposal [0] of Nick
Knight, the plan is that after this patch-set, all non-policy
intrinsics will be aligned with default policy behavior of tail
agnostic and mask undisturbed. Then the next patch-set will aim
towards changing non-policy intrinsics to tail agnostic and mask
agnostic.

[0] https://gist.github.com/nick-knight/6cb0b74b351a25323dfb1821d3a269b9

Pull Request: riscv-non-isa/rvv-intrinsic-doc#186

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D140895