build failure on Ubuntu22.04 from SIGSTKSZ not being an integer literal

In file included from /usr/include/signal.h:328,
                 from /home/derek/dr/git/src/core/drlibc/../lib/globals_shared.h:78,
                 from /home/derek/dr/git/src/core/drlibc/drlibc.h:47,
                 from /home/derek/dr/git/src/suite/tests/tools.h:46,
                 from /home/derek/dr/git/src/suite/tests/tools.c:35:
/home/derek/dr/git/src/suite/tests/tools.h:92:25: error: missing binary operator before token "("
   92 | #if defined(AARCH64) && SIGSTKSZ < 16384
      |                         ^~~~~~~~
[1021/1445] Building ASM object suite/tests/CMakeFiles/tools.dir/tools.c_asm.asm.o

It must be from this:

/usr/include/x86_64-linux-gnu/bits/sigstksz.h:# define SIGSTKSZ sysconf (_SC_SIGSTKSZ)