This adds a CMake option (defaults to OFF to not be intrusive) to activate 2 new targets install-unwind-headers and install-unwind-headers-stripped.
So, for example:
cmake -S runtimes -B build -G Ninja \ -DLLVM_ENABLE_RUNTIMES='libunwind' \ -DLIBUNWIND_INSTALL_HEADERS=ON
And then, ninja -C build install-unwind would install headers in addition to good ol' dylibs and archives, i.e., targets install-unwind* DEPENDS on install-unwind-headers*
On the other hand, ninja -C build install-unwind-headers gives you headers only.