[Bug libstdc++/86450] Bootstrap failure due to -Wabi

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86450

--- Comment #14 from Jonathan Wakely <redi at gcc dot gnu.org> ---
Because we haven't decided what the fix is.

Something like this seems better than dealing with each warning one by one
every time this happens:

--- a/libstdc++-v3/acinclude.m4
+++ b/libstdc++-v3/acinclude.m4
@@ -144,7 +144,8 @@ AC_DEFUN([GLIBCXX_CHECK_COMPILER_FEATURES], [
   if test x"$USE_MAINTAINER_MODE" = xno; then
     WERROR=''
   else
-    WERROR='-Werror'
+    # -Werror breaks the build too often, don't enable it.
+    WERROR=''
   fi

   # Check for -ffunction-sections -fdata-sections