http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60160
--- Comment #2 from Markus Trippelsdorf <trippels at gcc dot gnu.org> ---
libstdc++ also causes problems:
/var/tmp/gcc_build_dir_/./prev-gcc/xg++ -B/var/tmp/gcc_build_dir_/./prev-gcc/
-B/usr/x86_64-pc-linux-gnu/bin/ -nostdinc++
-B/var/tmp/gcc_build_dir_/prev-x86_64-pc-linux-gnu/l
ibstdc++-v3/src/.libs
-B/var/tmp/gcc_build_dir_/prev-x86_64-pc-linux-gnu/libstdc++-v3/libsupc++/.libs
-I/var/tmp/gcc_build_dir_/prev-x86_64-pc-linux-gnu/libstdc++-v3/include/
x86_64-pc-linux-gnu
-I/var/tmp/gcc_build_dir_/prev-x86_64-pc-linux-gnu/libstdc++-v3/include
-I/var/tmp/gcc/libstdc++-v3/libsupc++
-L/var/tmp/gcc_build_dir_/prev-x86_64-pc-lin
ux-gnu/libstdc++-v3/src/.libs
-L/var/tmp/gcc_build_dir_/prev-x86_64-pc-linux-gnu/libstdc++-v3/libsupc++/.libs
-march=native -O3 -pipe -flto=jobserver -frandom-seed=1 -fprof
ile-generate -fno-lto -DIN_GCC -fno-exceptions -fno-rtti
-fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings
-Wcast-qual -Wmissing-format-attribute -pedan
tic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings
-DHAVE_CONFIG_H -DGENERATOR_FILE
-Wl,-O1,--hash-style=gnu,--as-needed,--gc-sections,--icf=safe,--icf-iterati
ons=3 -o build/genconstants \
build/genconstants.o build/read-md.o build/errors.o
.././libiberty/libiberty.a
/var/tmp/gcc_build_dir_/prev-x86_64-pc-linux-gnu/libstdc++-v3/src/.libs/libstdc++.so:
error: undefined reference to 'std::istream::ignore(long)'
/var/tmp/gcc_build_dir_/prev-x86_64-pc-linux-gnu/libstdc++-v3/src/.libs/libstdc++.so:
error: undefined reference to 'std::basic_istream<wchar_t,
std::char_traits<wchar_t> >::
ignore(long)'
