Add implementation of fdprintf, clearenv, and stubs for ttyname_r, *usershell

Change-Id:	I5fe7e8b6ee5edbb49e707c3b6737a58563781fa3
diff --git a/libc/Android.mk b/libc/Android.mk
index 0d3e2c3..c32cc30 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -222,11 +222,13 @@
 	bionic/arc4random.c \
 	bionic/basename.c \
 	bionic/basename_r.c \
+	bionic/clearenv.c \
 	bionic/dirname.c \
 	bionic/dirname_r.c \
 	bionic/drand48.c \
 	bionic/erand48.c \
 	bionic/err.c \
+	bionic/fdprintf.c \
 	bionic/fork.c \
 	bionic/fts.c \
 	bionic/if_nametoindex.c \