lang/gcc13: Fix SIGBUS depending on CPUTYPE

Compiling GCC with some CPUTYPE values (e.g. broadwell) result in
breaking some applications (e.g. math/octave, cad/freecad), sending
a SIGBUS.

The issue is due to GCC generating instructions that require variables
to be aligned in memory on certain CPUs. Our libthr does not have the
required alignment so these CPUs fail to execute these instructions.

The patch disables the generation of such instructions and will get
obsolete once all supported FreeBSD releases include commit
22e564c74eb20e14bd93fd9fdde20e38a29cfcf1.

PR: 285711
Reported by: cracauer
Tested by: cracauer, jbo