[mlir][affine] Add canonicalization to merge affine min/max ops

This identifies a pattern where the producer affine min/max op
is bound to a dimension/symbol that is used as a standalone
expression in the consumer affine op's map. In that case the
producer affine min/max op can be merged into its consumer.

For example, a pattern like the following:

```
  %0 = affine.min affine_map<()[s0] -> (s0 + 16, s0 * 8)> ()[%sym1]
  %1 = affine.min affine_map<(d0)[s0] -> (s0 + 4, d0)> (%0)[%sym2]
```

Can be turned into:

```
  %1 = affine.min affine_map<
         ()[s0, s1] -> (s0 + 4, s1 + 16, s1 * 8)> ()[%sym2, %sym1]
```

Differential Revision: https://reviews.llvm.org/D99016