927092b262
Based on the discussion in https://discourse.llvm.org/t/rfc-execute-only-code-support-for-runtime-libraries-on-aarch64/86180 a single, global configuration option should be used to enable execute-only code generation for the runtime libraries. The new option `RUNTIMES_EXECUTE_ONLY_CODE` adds the `-mexecute-only` flag to `CMAKE_C_FLAGS` and `CMAKE_CXX_FLAGS`, which simplifies the library-level configuration needed for the runtime libraries. Project-specific changes are still needed to handle assembly sources, e.g. in compiler-rt and libunwind.