[libunwind] Fix compilation for the x32 ABI. (#116608)

This would previously fail the static assertions in `UnwindCursor.hpp`
due to `UnwindCursor`'s size not matching `unw_cursor_t`'s size. As is
done for MIPS N32, this just declares the appropriate size in
`__libunwind_config.h`.

GitOrigin-RevId: eb1f9cced9e878362aeac18e120895995f759ee3
1 file changed
tree: 1e197e399e35b78d78fff99e7ad0ba4bade4bfe4
  1. cmake/
  2. docs/
  3. include/
  4. src/
  5. test/
  6. .clang-format
  7. CMakeLists.txt
  8. LICENSE.TXT