Over estimation of persistent buffer size when project persistent buffer to its persistent producers

[liqiangxl]

In normalization scheduler, if project_persistent_buffers = True, PersistentBufferProjector will project persistent tvs to inputs, otherwise it trys to project persistent tvs to its immediate persistent producers. See #419 and #343

However, the buffer size was over estimated in scheduler_utils::persistentBufferSize. This overestimation occurs because the potential to project persistent tvs onto their immediate persistent producers isn't factored into the calculations.

For example, in the following fusion, T7 and T11 are persistent, both of them can be projected to inputs. The current calculated persistent_buffer_size is based on the reduction dim of T7 and T11. The projected_persistent_buffer_size is based on the correponding dim of inputs T0, T1, and T2. If the inputs are fp16, the projected_persistent_buffer_size is smaller than persistent_buffer_size and project_persistent_buffers = True.
However, since T11 can be projected back to T7, the correct value of persistent_buffer_size should only include the reduction dim of T7. Then, the projected_persistent_buffer_size is larger than persistent_buffer_size and the correct value of project_persistent_buffers should be False.

[liqiangxl]

fixed.