sel4bench fails to build on gcc-11

[lsf37]

See also seL4/sel4bench-manifest#16 -- gcc-11 is producing a segfault when compiling ipc.c in sel4bench:

[76/258] Building C object apps/sel4bench/projects_libs/libjansson/CMakeFiles/jansson.dir/jansson-2.7/src/load.c.obj
...
<continue error message>
...
/home/dinuka/Research/sel4bench/projects/sel4bench/apps/sel4bench/src/ipc.c: In function ‘process_ipc_results’:
/home/dinuka/Research/sel4bench/projects/sel4bench/apps/sel4bench/src/ipc.c:40:27: internal compiler error: Segmentation fault
   40 |         overhead_result = process_result(RUNS - 1, raw_results->overhead_benchmarks[i], desc);
      |                           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
0x770a5644251f ???
	./signal/../sysdeps/unix/sysv/linux/x86_64/libc_sigaction.c:0
0x770a56429d8f __libc_start_call_main
	../sysdeps/nptl/libc_start_call_main.h:58
0x770a56429e3f __libc_start_main_impl
	../csu/libc-start.c:392
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <file:///usr/share/doc/gcc-11/README.Bugs> for instructions.
ninja: build stopped: subcommand failed.