unwind: unify _LIBUNWIND_ABORT

Rather than use the `__assert_rtn` on libSystem based targets and a local
`assert_rtn` function on others, expand the function definition into a macro
which will perform the writing to stderr and then abort.  This unifies the
definition and behaviour across targets.

Ensure that we flush stderr prior to aborting.

git-svn-id: https://llvm.org/svn/llvm-project/libunwind/trunk@267364 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed
tree: 841d81a70550970718428f4972ab18d8b38eff86
  1. cmake/
  2. include/
  3. src/
  4. test/
  5. .arcconfig
  6. .clang-format
  7. CMakeLists.txt