Strided masked reductions: sum, amax. Testing of masked reductions. (#65990)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/65990
cc nikitaved pearu cpuhrsch IvanYashchuk
Test Plan: Imported from OSS
Reviewed By: zou3519
Differential Revision: D31729532
Pulled By: albanD
fbshipit-source-id: 855a6bb2a7c6e75c780a64ce23c0f29321f0e511
