[main] Move CDE intrinsics out of BETA stage

[fpetrogalli]

The CDE intrinsics are specified here: https://arm-software.github.io/acle/main/acle.html#custom-datapath-extension-1

This issue is to track what needs to be done and agreed to be able to remove the intrinsics out of BETA quality.

[fpetrogalli]

As reported by @miyuki:

The spec says: "These intrinsics are polymorphic in the T, U and V types, which must be of size 128 bits." But in LLVM we limit these types to 128-bit MVE vectors, not arbitrary 128-bit types.

See https://reviews.llvm.org/D76299