[lldb] Move create_relative_symlink function up in CMake hierarchy

Configuring lldb with `LLDB_ENABLE_PYTHON=OFF` and `LLDB_ENABLE_LUA=ON` results in a CMake error:

    CMake Error at lldb/bindings/lua/CMakeLists.txt:47 (create_relative_symlink):
      Unknown CMake command "create_relative_symlink".
    Call Stack (most recent call first):
      lldb/CMakeLists.txt:117 (finish_swig_lua)

This is because the CMake function `create_relative_symlink` only exists in `lldb/bindings/python/CMakeLists.txt`, and not in `lldb/bindings/lua/CMakeLists.txt`.

Move the function to `lldb/bindings/CMakeLists.txt`, so it is available for all language bindings.

Reviewed By: labath

Differential Revision: https://reviews.llvm.org/D114465

GitOrigin-RevId: b5a927b972b2c07b4597e93ed0b57803bfc0e6ae
2 files changed