[Bug bootstrap/120707] Comparing stage 2 and 3 fails because of rust-tyty-subst.o, building in src and -O3

[dilyan.palauzov at aegee dot org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=120707

--- Comment #7 from Дилян Палаузов <dilyan.palauzov at aegee dot org> ---
I was using all the time out-of-source/VPATH builds, but typed here ./configure
for simplicity.