libc: Update to master

alexcrichton · alexcrichton · commit 911cdbc51946 · 2015-11-22T11:29:12.000-08:00
Includes rust-lang/libc#66 which should: Closes #29956
diff --git a/src/liblibc b/src/liblibc
@@ -1 +1 @@
-Subproject commit 8531cc11e196b7ae9072ae7b384a930ff7b00dfb
+Subproject commit c27f4167a7706baba1ddbb0a9ab320ec18d097db
