Fixes cmake build for android.
pthread is built into libc, so the build fails if you try to link against it. (See https://developer.android.com/ndk/guides/stable_apis#c_library .)
The tester program can't be built though, since pthread_cancel is not implemented on android.
Fixes cmake build for android.
`pthread` is built into `libc`, so the build fails if you try to link against it. (See https://developer.android.com/ndk/guides/stable_apis#c_library .)
The tester program can't be built though, since `pthread_cancel` is not implemented on android.