Add sync_file_range to <fcntl.h>.

Bug: http://b/27952303
Change-Id: Idadfacd657ed415abc11684b9471e4e24c2fbf05
diff --git a/libc/Android.mk b/libc/Android.mk
index aed7087..0e4dc11 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -199,6 +199,7 @@
     bionic/strtold.cpp \
     bionic/stubs.cpp \
     bionic/symlink.cpp \
+    bionic/sync_file_range.cpp \
     bionic/sysinfo.cpp \
     bionic/syslog.cpp \
     bionic/sys_siglist.c \