[Bug libstdc++/77814] build fails trying to build eh_arm

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77814

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
testsuite/17_intro/headers/c++2011/linkage.cc should have caught this, but
didn't due to <ccomplex> hiding the problem.