Something

usr/src/gnu/usr.bin/cc/cc1plus/../cc_tools -I/usr/src/gnu/usr.bin/cc/cc1plus/../cc_tools -I/usr/src/gnu/usr.bin/cc/cc1plus/../../../../contrib/gcc -I/usr/src/gnu/usr.bin/cc/cc1plus/../../../../contrib/gcc/config -I/usr/src/gnu/usr.bin/cc/cc1plus/../../../../contrib/gcc/cp -I.  -I/usr/obj/usr/src/tmp/legacy/usr/include -c /usr/src/gnu/usr.bin/cc/cc1plus/../../../../contrib/gcc/cp/tree.c
/usr/src/gnu/usr.bin/cc/cc1plus/../../../../contrib/gcc/cp/tree.c: In function `cp_build_qualified_type_real':
/usr/src/gnu/usr.bin/cc/cc1plus/../../../../contrib/gcc/cp/tree.c:550: internal compiler error: Illegal instruction: 4
Please submit a full bug report,
with preprocessed source if appropriate.
See <URL:http://gcc.gnu.org/bugs.html> for instructions.
*** Error code 1

Stop in /usr/src/gnu/usr.bin/cc/cc1plus.
*** Error code 1

Stop in /usr/src/gnu/usr.bin/cc.
*** Error code 1

Stop in /usr/src.
*** Error code 1

Stop in /usr/src.
*** Error code 1

Stop in /usr/src.
# make buildworld