[StreamExecutor] Clean up device copy comments

Summary:
Consolidate Executor::synchronousCopy* and Stream::thenCopy* methods into
Doxygen method groups and combine all their comments into one section.

Also a "doc" target to the build files to use Doxygen to build the
documentation.

Reviewers: jlebar

Subscribers: jprice, parallel_libs-commits

Differential Revision: https://reviews.llvm.org/D23845

llvm-svn: 279654
GitOrigin-RevId: 424fc7e6118abbfbc3b1485435948a4d5f307f45
4 files changed
tree: 128e6099b28910ce44b9c17c0d2bb9c741e517c2
  1. .arcconfig
  2. .clang-format
  3. README.rst
  4. streamexecutor/