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/alpha/bits/mathdef.h

@@ -0,0 +1,60 @@
+/* Copyright (C) 1997-2014 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   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/>.  */
+
+#if !defined _MATH_H && !defined _COMPLEX_H
+# error "Never use <bits/mathdef.h> directly; include <math.h> instead"
+#endif
+
+/* FIXME! This file describes properties of the compiler, not the machine;
+   it should not be part of libc!  */
+
+#if defined __USE_ISOC99 && defined _MATH_H && !defined _MATH_H_MATHDEF
+# define _MATH_H_MATHDEF	1
+
+/* Alpha has "float" and "double" operations.  */
+typedef float float_t;    /* float expressions are evaluated as float.  */
+typedef double double_t;  /* double expressions are evaluated as double.  */
+
+/* The values returned by `ilogb' for 0 and NaN respectively.  */
+# define FP_ILOGB0     (-2147483647)
+# define FP_ILOGBNAN   (2147483647)
+
+#endif	/* ISO C99 && MATH_H */
+
+#if defined _COMPLEX_H && !defined _COMPLEX_H_MATHDEF
+# define _COMPLEX_H_MATHDEF 1
+# if defined(__GNUC__) && !__GNUC_PREREQ(3,4)
+
+/* Due to an ABI change, we need to remap the complex float symbols.  */
+#  define _Mdouble_		float
+#  define __MATHCALL(function, args) \
+    __MATHDECL (_Complex float, function, args)
+#  define __MATHDECL(type, function, args) \
+    __MATHDECL_1(type, function##f, args, __c1_##function##f); \
+    __MATHDECL_1(type, __##function##f, args, __c1_##function##f)
+#  define __MATHDECL_1(type, function, args, alias) \
+    extern type function args __asm__(#alias) __THROW
+
+#  include <bits/cmathcalls.h>
+
+#  undef _Mdouble_
+#  undef __MATHCALL
+#  undef __MATHDECL
+#  undef __MATHDECL_1
+
+# endif /* GNUC before 3.4 */
+#endif /* COMPLEX_H */