Run Miri tests with strict provenance

[lopopolo]

See:

• add -Zmiri-strict-provenance rust-lang/miri#2045

The current hard mode is:

$ MIRIFLAGS="-Zmiri-strict-provenance -Zmiri-check-number-validity -Zmiri-symbolic-alignment-check -Zrandomize-layout" cargo +nightly miri test --test leak_drop

Blockers:

• Miri with strict provenance flags UB in macos impl of hashmap_random_keys rust-lang/rust#96163

[CAD97]

(-Zmiri-strict-provenance implies -Zmiri-check-number-validity now.)

In the meantime, you can use --target to avoid testing the macOS target. (Miri, as an interpreter VM, can test any target on any host.)

[lopopolo]

Thanks for fixing this on macOS with rust-lang/rust#96167 @CAD97. The tests pass locally on my Mac for me now with rustc 1.62.0-nightly (f4ec0e7cf 2022-04-22).

PR to enable this is:

• Run Miri tests under strict provenance and randomize layout #157