Add pthread_getaffinity_np()/pthread_setaffinity_np().

Bug: http://b/18536425
Change-Id: I033fe25044367db0a01db027e6234d29eb2e8b95
diff --git a/libc/libc.map.txt b/libc/libc.map.txt
index d8636a2..86dcc39 100644
--- a/libc/libc.map.txt
+++ b/libc/libc.map.txt
@@ -1612,6 +1612,8 @@
   global:
     lchmod;
     mseal;
+    pthread_getaffinity_np;
+    pthread_setaffinity_np;
     qsort_r;
     sig2str;
     str2sig;