Fix sparc32 bits/long-double.h (bug 21987).

My refactoring of long double information

commit 0acb8a2a855395c25b1feef2470f4d7ca4bed589
Author: Joseph Myers <joseph@codesourcery.com>
Date:   Wed Dec 14 18:27:56 2016 +0000

    Refactor long double information into bits/long-double.h.

resulted in sparc32 configurations installing the ldbl-opt version of
bits/long-double.h instead of the intended
sysdeps/unix/sysv/linux/sparc version.

For sparc32 by itself, this is not a problem, since the ldbl-opt
version is correct for sparc32.  However, both sparc32 and sparc64 are
supposed to install sets of headers that work for both of them, so
that a single sysroot, whichever order the libraries are built and
installed in, works for both.  The effect of having the wrong version
installed is that you end up with a miscompiled sparc64 libstdc++
which fails glibc's configure tests for the C++ compiler.

This patch moves the header from sysdeps/unix/sysv/linux/sparc to
separate copies of the same file for sparc32 and sparc64, to ensure it
comes before ldbl-opt in the sysdeps directory ordering.

Tested with build-many-glibcs.py for sparc64-linux-gnu and
sparcv9-linux-gnu.

	[BZ #21987]
	* sysdeps/unix/sysv/linux/sparc/bits/long-double.h: Remove file
	and copy to ...
	* sysdeps/unix/sysv/linux/sparc/sparc32/bits/long-double.h:
	... here.
	* sysdeps/unix/sysv/linux/sparc/sparc64/bits/long-double.h:
	... and here.

2 files changed, 26 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/sparc/bits/long-double.h b/sysdeps/unix/sysv/linux/sparc/sparc32/bits/long-double.h
index 094e05124b..094e05124b 100644
--- a/sysdeps/unix/sysv/linux/sparc/bits/long-double.h
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/bits/long-double.h
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/bits/long-double.h b/sysdeps/unix/sysv/linux/sparc/sparc64/bits/long-double.h
new file mode 100644
index 0000000000..094e05124b
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/bits/long-double.h
@@ -0,0 +1,26 @@
+/* Properties of long double type.  SPARC version.
+   Copyright (C) 2016-2017 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  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 <bits/wordsize.h>
+
+#if !defined __NO_LONG_DOUBLE_MATH && __WORDSIZE == 32
+# define __LONG_DOUBLE_MATH_OPTIONAL   1
+# ifndef __LONG_DOUBLE_128__
+#  define __NO_LONG_DOUBLE_MATH        1
+# endif
+#endif