https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100017
--- Comment #71 from Jonathan Wakely <redi at gcc dot gnu.org> --- Tomorrow I'll test my more complete patch based on comment 7 (and comment 12) as that should also solve it, and without changes to configury. Conceptually, adding -nostdinc++ seems cleaner (it's what we already do when building the target libs with the just-built gcc) but I'm less certain about unwanted side effects.
