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/swap.h b/libc/include/sys/swap.h
index e79af97..8a30cce 100644
--- a/libc/include/sys/swap.h
+++ b/libc/include/sys/swap.h
@@ -38,9 +38,9 @@
 #define SWAP_FLAG_PRIO_MASK 0x7fff
 #define SWAP_FLAG_PRIO_SHIFT 0
 
-int swapon(const char*, int) __INTRODUCED_IN(19);
-int swapoff(const char*) __INTRODUCED_IN(19);
+int swapon(const char* __path,  int __flags) __INTRODUCED_IN(19);
+int swapoff(const char* __path) __INTRODUCED_IN(19);
 
 __END_DECLS
 
-#endif /* _SYS_SWAP_H_ */
+#endif