new gcc8/gcc10 build breakage between 9.99.63 and 9.99.67

[Thomas Klausner <wiz%NetBSD.org@localhost>]

Hi!

I've updated my system from 9.99.63 to 9.99.67.

I did a bulk build just before that and one right after, i.e. I have
binary packages from June 16.

After the upgrade, gcc8 and gcc10 do not build any longer because of
differences in the stage2 and stage3 files.

gcc8:

gmake[3]: Leaving directory '/scratch/lang/gcc8/work/build'
Comparing stages 2 and 3
warning: gcc/cc1obj-checksum.o differs
warning: gcc/cc1objplus-checksum.o differs
Bootstrap comparison failure!
gcc/crtbegin.o differs
gcc/crtend.o differs
gcc/crtbeginS.o differs
gcc/crtendS.o differs
gcc/crtbeginT.o differs
gmp/mpf/init.o differs
...

gcc10:

gmake[3]: Leaving directory '/scratch/lang/gcc10/work/build'
Comparing stages 2 and 3
warning: gcc/cc1obj-checksum.o differs
warning: gcc/cc1objplus-checksum.o differs
Bootstrap comparison failure!
gcc/build/version.o differs
gcc/version.o differs
gcc/crtbegin.o differs
gcc/crtend.o differs
gcc/crtendS.o differs
gcc/crtbeginT.o differs
gmp/mpf/init2.o differs
gmp/mpf/set_z.o differs
gmp/mpf/iset_str.o differs
gmp/mpf/clear.o differs

Does anyone have an idea what could have changed to break this?
 Thomas