Move several vector intrinsics out of experimental namespace (#88748)

This patch is moving out following intrinsics:
* vector.interleave2/deinterleave2
* vector.reverse
* vector.splice

from the experimental namespace.

All these intrinsics exist in LLVM for more than a year now, and are
widely used, so should not be considered as experimental.

mlir/lib/Conversion/VectorToLLVM/ConvertVectorToLLVM.cpp

@@ -1738,7 +1738,7 @@ struct VectorInterleaveOpLowering
                                          "InterleaveOp not rank 1");
     // If the result is rank 1, then this directly maps to LLVM.
     if (resultType.isScalable()) {
-      rewriter.replaceOpWithNewOp<LLVM::experimental_vector_interleave2>(
+      rewriter.replaceOpWithNewOp<LLVM::vector_interleave2>(
           interleaveOp, typeConverter->convertType(resultType),
           adaptor.getLhs(), adaptor.getRhs());
       return success();