Abort instead of panic on asserting intrinsics
This fixes#1222
replacing the panic with an abort and a corresponding message.
the stack trace is already printed, this just adds an optional message the caller can pass, and I just pass the same message we passed to the panic but now to the abort instead.
r? @RalfJung
Environ shim
Remake of https://github.com/rust-lang/miri/pull/1147. There are three main problems with this:
1. For some reason `update_environ` is not updating `environ` when `setenv` or `unsetenv` are called. Even then it works during initialization.
2. I am not deallocating the old array with the variables in `update_environ`.
3. I had to store the `environ` place into `MemoryExtra` as a field to update it. I was thinking about changing `extern_statics` to store places instead of `AllocID`s to avoid this.
@RalfJung
Add directory-related shims
This PR adds support for `mkdir`, `rmdir`, `opendir`, `closedir`, and `readdir64_r`.
Open directory streams are tracked through a HashMap indexed by pointer locations, which holds directory iterators. Since `DIR` is an opaque type in glibc, I represent them with 1-byte allocations, and then just use their pointers in HashMap lookups.
Tests are included to exercise the new functionality.
Add shim for rename
This adds a straightforward shim for rename, which is used by `std::fs::rename`. Testing is included.
As a heads up, I expect one or two merge conflicts between my PRs, since some of them touch the same `use` statements, or add items near the same places. I'll rebase and fix them as they come up.
