[Bug middle-end/70831] [6/7 Regression] FTBFS: Build fails with bootstrap-lto and profiledbootstrap

[t at sharklasers dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70831

--- Comment #12 from JD <t at sharklasers dot com> ---
My CPU is Intel Core i7-4800MQ, but I realized my report was misleading.
I get that same error with

LDFLAGS=-flto
CXXFLAGS=-flto
CFLAGS=-flto

which results in
"CFLAGS=-g -O2 -flto" "CXXFLAGS=-g -O2 -flto -D_GNU_SOURCE"
"CFLAGS_FOR_BUILD=-flto" "CFLAGS_FOR_TARGET=-g -O2 -flto"

and

$gcc-6.3.0/configure --prefix=/home/local/gcc-6.3.0lto --enable-languages=c
--with-build-config=bootstrap-lto --disable-multilib

and the error is in
Makefile:369: recipe for target 'libmpxwrappers.la' failed