alpha: force old OSF1 syscalls for getegid, geteuid and getppid [BZ #24986]

On alpha, Linux kernel 5.1 added the standard getegid, geteuid and
getppid syscalls (commit ecf7e0a4ad15287). Up to now alpha was using
the corresponding OSF1 syscalls through:
 - sysdeps/unix/alpha/getegid.S
 - sysdeps/unix/alpha/geteuid.S
 - sysdeps/unix/alpha/getppid.S

When building against kernel headers >= 5.1, the glibc now use the new
syscalls through sysdeps/unix/sysv/linux/syscalls.list. When it is then
used with an older kernel, the corresponding 3 functions fail.

A quick fix is to move the OSF1 wrappers under the
sysdeps/unix/sysv/linux/alpha directory so they override the standard
linux ones. A better fix would be to try the new syscalls and fallback
to the old OSF1 in case the new ones fail. This can be implemented in
a later commit.

Changelog:
	[BZ #24986]
        * sysdeps/unix/alpha/getegid.S: Move to ...
	* sysdeps/unix/sysv/linux/alpha/getegid.S: ... here.
        * sysdeps/unix/alpha/geteuid.S: Move to ...
	* sysdeps/unix/sysv/linux/alpha/geteuid.S: ... here.
        * sysdeps/unix/alpha/getppid.S: Move to ...
	* sysdeps/unix/sysv/linux/alpha/getppid.S: ... here

ChangeLog

@@ -1,3 +1,13 @@
+2019-09-14  Aurelien Jarno  <aurelien@aurel32.net>
+
+	[BZ #24986]
+        * sysdeps/unix/alpha/getegid.S: Move to ...
+	* sysdeps/unix/sysv/linux/alpha/getegid.S: ... here.
+        * sysdeps/unix/alpha/geteuid.S: Move to ...
+	* sysdeps/unix/sysv/linux/alpha/geteuid.S: ... here.
+        * sysdeps/unix/alpha/getppid.S: Move to ...
+	* sysdeps/unix/sysv/linux/alpha/getppid.S: ... here
+
 2019-09-13  Wilco Dijkstra  <wdijkstr@arm.com>
 
 	* string/memmem.c (__memmem): Rewrite to improve performance.

NEWS

@@ -33,6 +33,8 @@ The following bugs are resolved with this release:
   [24228] old x86 applications that use legacy libio crash on exit
   [24476] dlfcn: Guard __dlerror_main_freeres with __libc_once_get (once)
   [24744] io: Remove the copy_file_range emulation
+  [24986] alpha: new getegid, geteuid and getppid syscalls used
+    unconditionally
 
 Security related changes: