get_range panics due to misaligned pointer dereference in Rust 1.70+

[boydgreenfield]

test bloom::test::test_bloom_filter ... ok
thread 'mmap_bitvec::test::test_bitvec_get_range' panicked at 'misaligned pointer dereference: address must be a multiple of 0x10 but is 0x102d70008', src/mmap_bitvec.rs:516:22
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
thread 'mmap_bitvec::test::test_bitvec_get_range' panicked at 'panic in a function that cannot unwind', library/core/src/panicking.rs:126:5
stack backtrace:
   0:        0x102a8b76c - std::backtrace_rs::backtrace::libunwind::trace::h0a647ce7e8dc2fab
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/../../backtrace/src/backtrace/libunwind.rs:93:5
   1:        0x102a8b76c - std::backtrace_rs::backtrace::trace_unsynchronized::hea920694a2a8ac80
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
   2:        0x102a8b76c - std::sys_common::backtrace::_print_fmt::h7b4e20c1da2ebb61
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/sys_common/backtrace.rs:65:5
   3:        0x102a8b76c - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::h819e9cbdf1a9e730
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/sys_common/backtrace.rs:44:22
   4:        0x102aa4974 - core::fmt::write::ha5e9bf3131ecb7c0
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/core/src/fmt/mod.rs:1254:17
   5:        0x102a88bf8 - std::io::Write::write_fmt::h414ce9994bf17404
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/io/mod.rs:1698:15
   6:        0x102a8b580 - std::sys_common::backtrace::_print::h28d98f2094da6d1d
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/sys_common/backtrace.rs:47:5
   7:        0x102a8b580 - std::sys_common::backtrace::print::h8072db0bbd5bcc3d
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/sys_common/backtrace.rs:34:9
   8:        0x102a8d134 - std::panicking::default_hook::{{closure}}::h2c85c5b0c2ede151
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panicking.rs:269:22
   9:        0x102a8cef4 - std::panicking::default_hook::hcf2f70992d02f6fe
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panicking.rs:288:9
  10:        0x102a61130 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::h4e1aa1fb8cd42a85
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/alloc/src/boxed.rs:1987:9
  11:        0x102a61130 - test::test_main::{{closure}}::h3dac9aefecf8bd3c
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/test/src/lib.rs:134:21
  12:        0x102a8d748 - <alloc::boxed::Box<F,A> as core::ops::function::Fn<Args>>::call::he07e730a14cc7476
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/alloc/src/boxed.rs:1987:9
  13:        0x102a8d748 - std::panicking::rust_panic_with_hook::h023af7f90b47eb8b
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panicking.rs:695:13
  14:        0x102a8d500 - std::panicking::begin_panic_handler::{{closure}}::h14283519edc1d634
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panicking.rs:580:13
  15:        0x102a8bb8c - std::sys_common::backtrace::__rust_end_short_backtrace::hc366c0b0cef5b747
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/sys_common/backtrace.rs:150:18
  16:        0x102a8d2d4 - rust_begin_unwind
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panicking.rs:578:5
  17:        0x102aaf52c - core::panicking::panic_nounwind_fmt::h48fca0782e5a5b33
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/core/src/panicking.rs:96:14
  18:        0x102aaf5a8 - core::panicking::panic_nounwind::hc8dbc36c10163a33
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/core/src/panicking.rs:126:5
  19:        0x102aaf6a0 - core::panicking::panic_cannot_unwind::h8bbe98643cda7e5c
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/core/src/panicking.rs:188:5
  20:        0x102a214e0 - <mmap_bitvec::mmap_bitvec::MmapBitVec as mmap_bitvec::bitvec::BitVector>::get_range::h152b9838683ec0b1
                               at /Users/boyd/OC/mmap-bitvec/src/mmap_bitvec.rs:491:5
  21:        0x102a29d14 - mmap_bitvec::mmap_bitvec::test::test_bitvec_get_range::h0d74f3ad994d039c
                               at /Users/boyd/OC/mmap-bitvec/src/mmap_bitvec.rs:716:13
  22:        0x102a225a0 - mmap_bitvec::mmap_bitvec::test::test_bitvec_get_range::{{closure}}::hc175bca7eb24cc0f
                               at /Users/boyd/OC/mmap-bitvec/src/mmap_bitvec.rs:703:32
  23:        0x102a265ec - core::ops::function::FnOnce::call_once::h1ffe4f16dc2ea92e
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/core/src/ops/function.rs:250:5
  24:        0x102a65094 - core::ops::function::FnOnce::call_once::hf57ab7414346cd3e
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/core/src/ops/function.rs:250:5
  25:        0x102a65094 - test::__rust_begin_short_backtrace::h8906971520158b86
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/test/src/lib.rs:655:18
  26:        0x102a640c4 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::h11f245024fa107de
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/alloc/src/boxed.rs:1973:9
  27:        0x102a640c4 - <core::panic::unwind_safe::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once::h63f566e6242f22d7
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/core/src/panic/unwind_safe.rs:271:9
  28:        0x102a640c4 - std::panicking::try::do_call::ha521304254b2b8a6
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panicking.rs:485:40
  29:        0x102a640c4 - std::panicking::try::h781279c66bc65dea
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panicking.rs:449:19
  30:        0x102a640c4 - std::panic::catch_unwind::h62f2c0243d7355ff
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panic.rs:140:14
  31:        0x102a640c4 - test::run_test_in_process::h8be0dc8553a2d668
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/test/src/lib.rs:678:27
  32:        0x102a640c4 - test::run_test::run_test_inner::{{closure}}::h3c1fd2f20901e638
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/test/src/lib.rs:572:39
  33:        0x102a36e70 - test::run_test::run_test_inner::{{closure}}::ha0406b263a72cd5b
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/test/src/lib.rs:599:37
  34:        0x102a36e70 - std::sys_common::backtrace::__rust_begin_short_backtrace::h01f0c6c7a98e3e15
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/sys_common/backtrace.rs:134:18
  35:        0x102a3b924 - std::thread::Builder::spawn_unchecked_::{{closure}}::{{closure}}::h160acb161c6a735a
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/thread/mod.rs:526:17
  36:        0x102a3b924 - <core::panic::unwind_safe::AssertUnwindSafe<F> as core::ops::function::FnOnce<()>>::call_once::h9ccec8dfc8841d99
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/core/src/panic/unwind_safe.rs:271:9
  37:        0x102a3b924 - std::panicking::try::do_call::h554d349d895c285b
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panicking.rs:485:40
  38:        0x102a3b924 - std::panicking::try::hafe9b48954d647a5
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panicking.rs:449:19
  39:        0x102a3b924 - std::panic::catch_unwind::h05668823152b5e98
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/panic.rs:140:14
  40:        0x102a3b924 - std::thread::Builder::spawn_unchecked_::{{closure}}::ha9617bcc6788886f
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/thread/mod.rs:525:30
  41:        0x102a3b924 - core::ops::function::FnOnce::call_once{{vtable.shim}}::hf7dcd4587efbbfa3
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/core/src/ops/function.rs:250:5
  42:        0x102a913e8 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hd96d02f907263858
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/alloc/src/boxed.rs:1973:9
  43:        0x102a913e8 - <alloc::boxed::Box<F,A> as core::ops::function::FnOnce<Args>>::call_once::hfd80494da4543cfb
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/alloc/src/boxed.rs:1973:9
  44:        0x102a913e8 - std::sys::unix::thread::Thread::new::thread_start::h7f56b35fafcfec87
                               at /rustc/90c541806f23a127002de5b4038be731ba1458ca/library/std/src/sys/unix/thread.rs:108:17
  45:        0x1968cbfa8 - __pthread_joiner_wake
thread caused non-unwinding panic. aborting.
error: test failed, to rerun pass `--lib`

See also onecodex/rust-bfield#20 for discussion of the issue.

[boydgreenfield]

Closed in #20