[SE] Clean up device and host memory slices

Summary:
* Add LLVM_ATTRIBUTE_UNUSED_RESULT used to slicing methods in order to
  emphasize that the slicing is not done in place.
* Change device memory slice function name from `drop_front` to `slice`
  in order to match the naming convention of `llvm::ArrayRef` and host
  memory slice.
* Change the parameter names of host memory slice functions to
  `DropCount` and `TakeCount` to match device memory slice declarations.

Reviewers: jlebar

Subscribers: jprice, parallel_libs-commits

Differential Revision: https://reviews.llvm.org/D24464

llvm-svn: 281239
GitOrigin-RevId: c16fb8748d0e8bbc72853f26cda012302206359b
4 files changed
tree: b12d48a214b151027023fe39b8b77162b97e68dc
  1. .arcconfig
  2. .clang-format
  3. CMakeLists.txt
  4. README.rst
  5. streamexecutor/