[X86][AVX] createVariablePermute - generalize the PR50356 fix for smaller indices vector as well

Generalize the fix from rGd0902a8665b1 by ensuring we widen/narrow the indices subvector first and then perform the ZERO_EXTEND_VECTOR_INREG (if necessary), which should allow us to perform the variable permutes with source/destination/indices vectors of any widths.