[clang] [CIR] Upstream ShuffleOp for VectorType (PR #142288)

[Henrich Lauko via cfe-commits]

xlauko wrote:


> `The size of the result vector does not have to match the size of the individual input vectors or of the concatenated vector.`

Quoiting the docs: the result of `__builtin_shufflevector` is a vector with the same element type as `vec1` and `vec2` but that has an element count equal to the number of indices specified.



https://github.com/llvm/llvm-project/pull/142288