[OP] Introduces auxiliary attrs into compute (#1293)

include/tvm/operation.h

include/tvm/runtime/c_runtime_api.h

python/tvm/api.py

src/api/api_lang.cc

src/lang/reflection.cc

src/op/compute_op.cc

src/op/extern_op.cc

src/op/scan_op.cc

src/schedule/schedule_dataflow_rewrite.cc

tests/python/unittest/test_lang_reflection.py

tests/python/unittest/test_lang_tag.py

topi/include/topi/contrib/cublas.h

topi/include/topi/contrib/rocblas.h

topi/include/topi/detail/extern.h