This test only fails with non-native 128-bit integers, but it will also
fail with native 128-bit integers if we copy/paste it so that it's
executed twice. Interestingly, wrapping the test in a loop won't make it
fail.
So, it could be due to stack space or unwinding in release mode.
Also, the test only fails with -O2:
../cargo.sh rustc --bin test-rust -- -O
It doesn't fail with -O3.
