Re-submit "Name function arguments in libc headers for Studio."

This reverts commit 9af9120091ceb96641d7c6c645fabad96db4bc0d (a revert
of 079bff4fa52b0c3c76057451cc9cdecf1827fce0), now the versioner bug is
fixed.

Bug: http://b/64613623 # header bug
Bug: http://b/64802958 # versioner bug
Change-Id: I1cb9d7832d4b3aecdc57a9285e2291443e59d02d
diff --git a/libc/include/sys/eventfd.h b/libc/include/sys/eventfd.h
index 6b9749a..3cfb5e7 100644
--- a/libc/include/sys/eventfd.h
+++ b/libc/include/sys/eventfd.h
@@ -37,14 +37,13 @@
 #define EFD_CLOEXEC O_CLOEXEC
 #define EFD_NONBLOCK O_NONBLOCK
 
-/* type of event counter */
 typedef uint64_t eventfd_t;
 
-int eventfd(unsigned int initial_value, int flags);
+int eventfd(unsigned int __initial_value, int __flags);
 
-int eventfd_read(int fd, eventfd_t* value);
-int eventfd_write(int fd, eventfd_t value);
+int eventfd_read(int __fd, eventfd_t* __value);
+int eventfd_write(int __fd, eventfd_t __value);
 
 __END_DECLS
 
-#endif /* _SYS_EVENTFD_H */
+#endif