-Bsymbolic-functions is not supported by our ld.bfd version.

Index: tools/llvm-shlib/CMakeLists.txt
--- tools/llvm-shlib/CMakeLists.txt.orig
+++ tools/llvm-shlib/CMakeLists.txt
@@ -50,7 +50,7 @@ if(LLVM_BUILD_LLVM_DYLIB)
       # Solaris ld does not accept global: *; so there is no way to version *all* global symbols
       set(LIB_NAMES -Wl,--version-script,${LLVM_LIBRARY_DIR}/tools/llvm-shlib/simple_version_script.map ${LIB_NAMES})
     endif()
-    if (NOT MINGW)
+    if (NOT MINGW AND ${OPENBSD_LD_IS_LLD})
       # Optimize function calls for default visibility definitions to avoid PLT and
       # reduce dynamic relocations.
       # Note: for -fno-pic default, the address of a function may be different from
