Add test for wrong code generation for HashSet creation on arm cpu
This is test for #42918.
To reproduce bug you need machine with arm cpu and compile with optimization.
I tried with rustc 1.19.0-nightly (3d5b8c626 2017-06-09),
if compile test with -C opt-level=3 for target=arm-linux-androideabi
and run on "Qualcomm MSM 8974 arm cpu" then assert fails,
if compile and run with -C opt-level=2 it gives segmentation fault.
So I add `compile-flags: -O`.
With rustc 1.19.0 (0ade33941 2017-07-17) all works fine.
Closes#42918
ff33b60a80