[Bug c++/104157] -std=libc++ does not with cross compilers and moving the install around (places the include path last)

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104157

--- Comment #11 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Somehow add_standard_paths is doing the wrong thing when -iprefix is applied
but I have no idea how or why. This definitely needs to be fixed but it is a
low priority as -std=libc++ is not used that much, especially with
non-sysrooted cross compilers.