9097e3cbca
(Note I am also applying this to main and stable/13, to restore the old libcxxrt ABI and to avoid having to maintain a compat library.) After the recent cherry-picking of libcxxrt commits 0ee0dbfb0d26 and d2b3fadf2db5, users reported that editors/libreoffice packages from the official package builders did not start anymore. It turns out that the combination of these commits subtly changes the ABI, requiring all applications that depend on internal details of struct _Unwind_Exception (available via unwind-arm.h and unwind-itanium.h) to be recompiled. However, the FreeBSD package builders always use -RELEASE jails, so these still use the old declaration of struct _Unwind_Exception, which is not entirely compatible. In particular, LibreOffice uses this struct in its internal "uno bridge" component, where it attempts to setup its own exception handling mechanism. To fix this incompatibility, go back to the old declarations of struct _Unwind_Exception, and restore the __LP64__ specific workaround we had in place before (which was to cope with yet another, older ABI bug). Effectively, this reverts upstream libcxxrt commits 88bdf6b290da ("Specify double-word alignment for ARM unwind") and b96169641f79 ("Updated Itanium unwind"), and reapplies our commit 3c4fd2463bb2 ("libcxxrt: add padding in __cxa_allocate_* to fix alignment"). PR: 253840