[X86][AMX] Fix the shape dependency issue.

AMX shape should be defined before AMX intrinsics. However for below
case, the shape a.row is defined after tile load of b. If we transform
`load b` to `@llvm.x86.tileloadd64 intrinsic`, the shape dependency
doesn't meet.
```
void test_tile_dpbsud(__tile1024i a, __tile1024i b, __tile1024i c) {
  __tile_dpbsud(&c, a, b);
}
```
This patch is to store the tile b to stack and reloaded it after the
def of b.row. It would cause redundant store/load, but it is simple
to avoid generating invalid IR.
The better way may hoist `def b.row` before tile load instruction,
but it seems more complicated to recursively hoist its operands.

Differential Revision: https://reviews.llvm.org/D137923