Use LLD as linker when we build with Clang.

CMakeLists.txt

@@ -18,6 +18,9 @@ if (SHARED)
     set(LIBTYPE SHARED)
 endif (SHARED)
 
+if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+    add_link_options(-fuse-ld=lld)
+endif ()
 
 if (NOT WINDOWS)
     # Include debug symbols in all linux builds