Fix build error with GCC by forcing Clang compiler in CMake on android/aarch64 (#242)

GCC does not recognize Clang-specific warning flags like
-Wunreachable-code-break and -Wunreachable-code-return, which are passed
by upstream submodules (e.g., ggml). This patch forces CMake to use Clang
via command-line arguments, avoiding the need to patch nested submodules.

This resolves compiler errors without modifying submodule source code.