Fix a few issues picked up by the address sanitizer. These are mostly related to unit tests, including one that leads to an occasional crash on Windows - #2651, and also:
Fix a heap-buffer-overflow in test case Address Sanitizer picked up a heap-buffer-overflow in CBoostedTreeTest/testEdgeCases. Rework the test slightly to avoid it.
Optimize code when running the Address Sanitizer Add the O3 flag to those used for compiling with the Address Sanitizer enabled. In most cases this is sufficient and cuts the run time significantly.
Fix a few issues picked up by the address sanitizer. These are mostly related to unit tests, including one that leads to an occasional crash on Windows - #2651, and also:
Fix a heap-buffer-overflow in test case Address Sanitizer picked up a heap-buffer-overflow in
CBoostedTreeTest/testEdgeCases. Rework the test slightly to avoid it.Optimize code when running the Address Sanitizer Add the
O3flag to those used for compiling with the Address Sanitizer enabled. In most cases this is sufficient and cuts the run time significantly.Backports #2738