[mlir][Vector] Add 16x16 strategy to vector.transpose lowering.

[mlir][Vector] Add 16x16 strategy to vector.transpose lowering.

It adds a `shuffle_16x16` strategy LowerVectorTranspose and renames `shuffle` to `shuffle_1d`. The idea is similar to 8x8 cases in x86Vector::avx2. The general algorithm is:

```
interleave 32-bit lanes using
    8x _mm512_unpacklo_epi32
    8x _mm512_unpackhi_epi32
interleave 64-bit lanes using
    8x _mm512_unpacklo_epi64
    8x _mm512_unpackhi_epi64
permute 128-bit lanes using
   16x _mm512_shuffle_i32x4
permute 256-bit lanes using again
   16x _mm512_shuffle_i32x4
```

After the first stage, they got transposed to

```
 0  16   1  17   4  20   5  21   8  24   9  25  12  28  13  29
 2  18   3  19   6  22   7  23  10  26  11  27  14  30  15  31
32  48  33  49 ...
34  50  35  51 ...
64  80  65  81 ...
...
```

After the second stage, they got transposed to

```
 0  16  32  48 ...
 1  17  33  49 ...
 2  18  34  49 ...
 3  19  35  51 ...
64  80  96 112 ...
65  81  97 114 ...
66  82  98 113 ...
67  83  99 115 ...
...
```

After the thrid stage, they got transposed to

```
  0  16  32  48   8  24  40  56  64  80  96  112 ...
  1  17  33  49 ...
  2  18  34  50 ...
  3  19  35  51 ...
  4  20  36  52 ...
  5  21  37  53 ...
  6  22  38  54 ...
  7  23  39  55 ...
128 144 160 176 ...
129 145 161 177 ...
...
```

After the last stage, they got transposed to

```
0  16  32  48  64  80  96 112 ... 240
1  17  33  49  66  81  97 113 ... 241
2  18  34  50  67  82  98 114 ... 242
...
15  31  47  63  79  96 111 127 ... 255
```

Reviewed By: dcaballe

Differential Revision: https://reviews.llvm.org/D148685