disable code which uses attribute(target_clones) to provide functions
optimized for different CPUs. apparently clang 15 adds supports for this,
but we don't have ifunc support in the toolchain, so it fails to link.

Index: src/common/darktable.h
--- src/common/darktable.h.orig
+++ src/common/darktable.h
@@ -150,7 +150,7 @@ extern "C" {
 /* Create cloned functions for various CPU SSE generations */
 /* See for instructions https://hannes.hauswedell.net/post/2017/12/09/fmv/ */
 /* TL;DR : use only on SIMD functions containing low-level paralellized/vectorized loops */
-#if __has_attribute(target_clones) && !defined(_WIN32) && !defined(NATIVE_ARCH) && !defined(__APPLE__)
+#if __has_attribute(target_clones) && !defined(_WIN32) && !defined(NATIVE_ARCH) && !defined(__APPLE__) && !defined(__OpenBSD__)
 # if defined(__amd64__) || defined(__amd64) || defined(__x86_64__) || defined(__x86_64)
 #define __DT_CLONE_TARGETS__ __attribute__((target_clones("default", "sse2", "sse3", "sse4.1", "sse4.2", "popcnt", "avx", "avx2", "avx512f", "fma4")))
 # elif defined(__PPC64__)
