android4.0 编译undefined reference to `pthread_mutex_trylock'

home/android/workspace/buildroid/external/llvm/lib/Support/Mutex.cpp:143: undefined reference to `pthread_mutex_trylock'

collect2: ld returned 1 exit status

make: *** [out/host/linux-x86/obj/EXECUTABLES/test-librsloader_intermediates/test-librsloader] Error 1

解决了，

解决方法：

解决办法：
vim external/llvm/llvm-host-build.mk
LOCAL_LDLIBS := -lpthread   -ldl