https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91085
--- Comment #12 from Bruce Korb <bkorb at gnu dot org> ---
I'll put it on my to-do list, but I might be participating in a fire evacuation
tonight or tomorrow and I haven't built GCC in several years now. I'm going to
guess that you have to not do the substitution when the line contains something
like:
#[ \t]*if[ \t]+__glibc_has
