Relocate alpha from ports to libc

Also fixed the following whitespace nits to satisfy the push:

sysdeps/alpha/alphaev6/memset.S:142: space before tab in indent.
sysdeps/alpha/configure:1: new blank line at EOF.
sysdeps/alpha/fpu/e_sqrt.c:126: space before tab in indent.
sysdeps/alpha/preconfigure:1: new blank line at EOF.
sysdeps/unix/sysv/linux/alpha/syscalls.list:1: new blank line at EOF.

sysdeps/unix/sysv/linux/alpha/sigprocmask.c

@@ -0,0 +1,57 @@
+/* Copyright (C) 1993-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by David Mosberger (davidm@azstarnet.com).
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library.  If not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <sysdep.h>
+#include <signal.h>
+
+/* When there is kernel support for more than 64 signals, we'll have to
+   switch to a new system call convention here.  */
+
+int
+__sigprocmask (int how, const sigset_t *set, sigset_t *oset)
+{
+  unsigned long int setval;
+  long result;
+
+  if (set)
+    setval = set->__val[0];
+  else
+    {
+      setval = 0;
+      how = SIG_BLOCK;	/* ensure blocked mask doesn't get changed */
+    }
+
+  result = INLINE_SYSCALL (osf_sigprocmask, 2, how, setval);
+  if (result == -1)
+    /* If there are ever more than 63 signals, we need to recode this
+       in assembler since we wouldn't be able to distinguish a mask of
+       all 1s from -1, but for now, we're doing just fine... */
+    return result;
+
+  if (oset)
+    {
+      oset->__val[0] = result;
+      result = _SIGSET_NWORDS;
+      while (--result > 0)
+	oset->__val[result] = 0;
+    }
+  return 0;
+}
+
+weak_alias (__sigprocmask, sigprocmask);