[Bug bootstrap/72823] [7 Regression] r239175 causes build failure

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=72823

--- Comment #8 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
I guess the thing is that ENABLE_ASSERT_CHECKING is never defined while
building libcpp, it is simply not handled by libcpp/configure* and not stored
in libcpp/config*.  So, either it could use CHECKING_P instead, or the
configury needs to be changed.