libstdc++-v3: Have aligned_alloc() on Newlib

While building for Newlib, some configure checks must be hard coded.
The aligned_alloc() is supported since 2015 in Newlib.

libstdc++-v3/

	PR target/85904
	* configure.ac: Define HAVE_ALIGNED_ALLOC if building for
	Newlib.
	* configure: Regenerate.

From-SVN: r263461

libstdc++-v3/ChangeLog

+2018-08-10  Sebastian Huber  <sebastian.huber@embedded-brains.de>
+
+	PR target/85904
+	* configure.ac: Define HAVE_ALIGNED_ALLOC if building for
+	Newlib.
+	* configure: Regenerate.
+
 2018-08-10  Jonathan Wakely  <jwakely@redhat.com>
 
 	* include/std/deque (std::pmr::deque): Declare alias.

libstdc++-v3/configure

@@ -28967,6 +28967,8 @@ else
     $as_echo "#define HAVE_TANHF 1" >>confdefs.h
 
 
+    $as_echo "#define HAVE_ALIGNED_ALLOC 1" >>confdefs.h
+
     $as_echo "#define HAVE_ICONV 1" >>confdefs.h
 
     $as_echo "#define HAVE_MEMALIGN 1" >>confdefs.h

libstdc++-v3/configure.ac

@@ -330,6 +330,7 @@ else
     AC_DEFINE(HAVE_TANF)
     AC_DEFINE(HAVE_TANHF)
 
+    AC_DEFINE(HAVE_ALIGNED_ALLOC)
     AC_DEFINE(HAVE_ICONV)
     AC_DEFINE(HAVE_MEMALIGN)
   else