[Bug target/88535] sparcv9 gcc 7 causes comparison failure in sparc gcc 8 dwarf2out.o

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88535

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
So that means host gcc 7 when defaulting to -m64 miscompiles stage1 in a way
that it miscompiles stage2 but that miscompilation does not affect stage3. 
That'll be "interesting" to track down :/