- Partially revert upstream commit b76d2fb1e5bb839249b25b7094db94219695f515,
  it breaks the build on OpenBSD.

Index: CMakeLists.txt
--- CMakeLists.txt.orig
+++ CMakeLists.txt
@@ -446,10 +446,6 @@ else() # MSVC
     add_compile_flag("-Wno-error=missing-field-initializers")
   endif()
 
-  if(NOT APPLE AND NOT "${CMAKE_CXX_FLAGS}" MATCHES "-fsanitize")
-    # This flag only applies to shared libraries so don't use add_link_flag
-    set(CMAKE_SHARED_LINKER_FLAGS "${CMAKE_SHARED_LINKER_FLAGS} -Wl,--no-undefined")
-  endif()
 
 endif()
 
