[libunwind] Add a from-scratch config for running libunwind tests

Running tests for libunwind is a lot simpler than running tests for
libc++, so a simple Lit config file is sufficient. The benefit is that
we disentangle the libunwind test configuration from the libc++ and
libc++abi test configuration. The setup was too complicated, which led
to some bugs (notably we were running against the system libunwind on
Apple platforms).

Differential Revision: https://reviews.llvm.org/D111664

GitOrigin-RevId: 6fd55bba61bb4df98f9485b8d3cfc9e956d992b8
10 files changed
tree: bed3c59dba9f87b22f6fafce9119b3831908155d
  1. .clang-format
  2. CMakeLists.txt
  4. cmake/
  5. docs/
  6. include/
  7. src/
  8. test/