boost: fix segfault in asio+align module.

Reported-by: Érico Nogueira <erico.erc@gmail.com>

srcpkgs/boost/patches/feature-test-macros.patch

@@ -0,0 +1,32 @@
+boost/align/aligned_alloc.hpp is wrong, it uses feature test macros to
+determine whether something is available;
+FTMs shouldn't be in user code outside of top level #define's.
+
+This lead to an issue on musl where libtorrent-rasterbar was including this
+header (via boost asio) from two different places, and segfaulting due to
+mismatched implementations -- one's the posix one using posix_memalign, the
+other one's the generic one that stores a pointer to itself.
+
+posix_memalign is always available on the libcs we support and should always be
+used, so we force that. We still leave applications with the option of forcing
+boost specific behavior, if they really want it.
+
+Instead of patching only boost/align/aligned_alloc.hpp, which fix the
+bug if boost::asio is used, but may keep other boost's code use feature tests
+macro, now or later, let's patch boost/config.hpp to always define
+_XOPEN_SOURCE instead.
+
+--- a/boost/config.hpp
++++ b/boost/config.hpp
+@@ -17,6 +17,11 @@
+ #ifndef BOOST_CONFIG_HPP
+ #define BOOST_CONFIG_HPP
+ 
++#ifdef __linux__
++/* for _XOPEN_SOURCE and/or _POSIX_C_SOURCE */
++#include <features.h>
++#endif
++
+ // if we don't have a user config, then use the default location:
+ #if !defined(BOOST_USER_CONFIG) && !defined(BOOST_NO_USER_CONFIG)
+ #  define BOOST_USER_CONFIG <boost/config/user.hpp>

srcpkgs/boost/template

@@ -1,7 +1,7 @@
 # Template file for 'boost'
 pkgname=boost
 version=1.80.0
-revision=1
+revision=2
 wrksrc="${pkgname}_${version//\./_}"
 hostmakedepends="which bzip2-devel icu-devel python3-devel pkg-config"
 makedepends="zlib-devel bzip2-devel icu-devel python3-devel liblzma-devel