https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85413
--- Comment #2 from Дилян Палаузов <dilyan.palauzov at aegee dot org> ---
config/bootstrap-lto.mk contains more tweaks:
# This option enables LTO for stage2 and stage3 in slim mode
STAGE2_CFLAGS += -flto=jobserver -frandom-seed=1
STAGE3_CFLAGS += -flto=jobserver -frandom-seed=1
STAGEprofile_CFLAGS += -fno-lto
# assumes the host supports the linker plugin
LTO_AR = $$r/$(HOST_SUBDIR)/prev-gcc/gcc-ar$(exeext)
-B$$r/$(HOST_SUBDIR)/prev-gcc/
LTO_RANLIB = $$r/$(HOST_SUBDIR)/prev-gcc/gcc-ranlib$(exeext)
-B$$r/$(HOST_SUBDIR)/prev-gcc/
LTO_EXPORTS = AR="$(LTO_AR)"; export AR; \
RANLIB="$(LTO_RANLIB)"; export RANLIB;
LTO_FLAGS_TO_PASS = AR="$(LTO_AR)" RANLIB="$(LTO_RANLIB)"
