Add fp16 to 8 gpu fp16 tests. (#6353)
Add fp16 to 8 gpu fp16 tests. (#6353)


alexgorban/models,alexgorban/models,tombstone/models,tombstone/models,alexgorban/models,tombstone/models,derekjchow/models,alexgorban/models,derekjchow/models,derekjchow/models,tombstone/models,tombstone/models,tombstone/models,alexgorban/models,derekjchow/models,derekjchow/models