compiler-rt: Use OpenBSD's elf_aux_info to detect AArch64 HW features (#155768)

Author: brad0

compiler-rt/lib/builtins/cpu_model/aarch64.c

@@ -34,7 +34,7 @@ typedef struct __ifunc_arg_t {
 _Bool __aarch64_have_lse_atomics
     __attribute__((visibility("hidden"), nocommon)) = false;
 
-#if defined(__FreeBSD__)
+#if defined(__FreeBSD__) || defined(__OpenBSD__)
 // clang-format off: should not reorder sys/auxv.h alphabetically
 #include <sys/auxv.h>
 // clang-format on
@@ -68,7 +68,7 @@ struct {
 // clang-format off
 #if defined(__APPLE__)
 #include "aarch64/fmv/apple.inc"
-#elif defined(__FreeBSD__)
+#elif defined(__FreeBSD__) || defined(__OpenBSD__)
 #include "aarch64/fmv/mrs.inc"
 #include "aarch64/fmv/elf_aux_info.inc"
 #elif defined(__Fuchsia__)