LightGBM

Fix access violation exception that can occur during invocation of loop lambda function when inner_start >= inner_end in 'For' template (#3936)

* Fix index out-of-range exception generated by BaggingHelper on small datasets.

Prior to this change, the line "score_t threshold = tmp_gradients[top_k - 1];" would generate an exception, since tmp_gradients would be empty when the cnt input value to the function is zero.

* Update goss.hpp

* Update goss.hpp

* Add API method LGBM_BoosterPredictForMats which runs prediction on a data set given as of array of pointers to rows (as opposed to existing method LGBM_BoosterPredictForMat which requires data given as contiguous array)

* Fix incorrect upstream merge

* Add link to LightGBM.NET

* Fix indenting to 2 spaces

* Dummy edit to trigger CI

* Dummy edit to trigger CI

* remove duplicate functions from merge

* Fix access violation exception that can occur during invocation of loop lambda function when inner_start >= inner_end in 'For' template.

In particular, this can occur in Tree::AddPredictionToScore on line 291 where the loop lambda function body (created by the PredictionFun macro) dereferences used_data_indices[start].

For reference, the particular case which triggered this exception in my case was:
  * start = 0
  * end = 93,203
  * n_block = 56
  * min_block_size = 512
for which the BlockInfo method gave:
  * n_block = 56
  * num_inner = 1,696
and so, for the case i=55 (i.e., the last case in the loop), we get
  * inner_start = start + num_inner * i
                = 93,280
which is greater than 'end' and hence triggers the exception.

* Change formatting of proposed modification

Co-authored-by: matthew-peacock <matthew.peacock@whiteoakam.com>
Co-authored-by: Guolin Ke <guolin.ke@outlook.com>