Patch for recent versions of glibc which always assume int64_t support.

Fixes compilation error with aarch64 target:

./boost/atomic/atomic.hpp: At global scope:
./boost/atomic/atomic.hpp:202:16: error: 'uintptr_t' was not declared in this scope
 typedef atomic<uintptr_t> atomic_uintptr_t;
                ^
./boost/atomic/atomic.hpp:202:25: error: template argument 1 is invalid
 typedef atomic<uintptr_t> atomic_uintptr_t;
                         ^
./boost/atomic/atomic.hpp:202:43: error: invalid type in declaration before ';' token
 typedef atomic<uintptr_t> atomic_uintptr_t;
                                           ^

Reported here: https://svn.boost.org/trac/boost/ticket/8973
Fix reported here: https://svn.boost.org/trac/boost/ticket/8731

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Backported-from: https://svn.boost.org/trac/boost/changeset/84950

--- a/boost/cstdint.hpp	(revision 84805)
+++ b/boost/cstdint.hpp	(revision 84950)
@@ -42,5 +42,8 @@
 // See https://svn.boost.org/trac/boost/ticket/3548 and http://sources.redhat.com/bugzilla/show_bug.cgi?id=10990
 //
-#if defined(BOOST_HAS_STDINT_H) && (!defined(__GLIBC__) || defined(__GLIBC_HAVE_LONG_LONG))
+#if defined(BOOST_HAS_STDINT_H)					\
+  && (!defined(__GLIBC__)					\
+      || defined(__GLIBC_HAVE_LONG_LONG)			\
+      || (defined(__GLIBC__) && ((__GLIBC__ > 2) || ((__GLIBC__ == 2) && (__GLIBC_MINOR__ >= 17)))))
 
 // The following #include is an implementation artifact; not part of interface.