Match std RUSTFLAGS for host and target for mir-opt test suite to fix double std build/rebuilds
#137710
| Job | Run time |
|---|---|
| 13s | |
| 35m 52s | |
| 6m 59s | |
| 1h 12m 52s | |
| 28m 32s | |
| 0s | |
| 2h 24m 28s |