Rollup merge of #100129 - RalfJung:miri-test-libstd, r=thomcc

add miri-test-libstd support to libstd

- The first commit mirrors what we already have in liballoc.
- The second commit adds some regression tests that only really make sense to be run in Miri, since they rely on Miri's extra checks to detect anything.
- The third commit makes the MPSC tests work in reasonable time in Miri by reducing iteration counts.
- The fourth commit silences some warnings due to code being disabled with `cfg(miri)`

1 files changed, 2 insertions, 0 deletions

diff --git a/library/std/src/sys/unix/fs.rs b/library/std/src/sys/unix/fs.rs
index 7778033eaa9..f38d2fd3d70 100644
--- a/library/std/src/sys/unix/fs.rs
+++ b/library/std/src/sys/unix/fs.rs
@@ -829,6 +829,7 @@ impl DirEntry {
         target_os = "fuchsia",
         target_os = "redox"
     )))]
+    #[cfg_attr(miri, allow(unused))]
     fn name_cstr(&self) -> &CStr {
         unsafe { CStr::from_ptr(self.entry.d_name.as_ptr()) }
     }
@@ -840,6 +841,7 @@ impl DirEntry {
         target_os = "fuchsia",
         target_os = "redox"
     ))]
+    #[cfg_attr(miri, allow(unused))]
     fn name_cstr(&self) -> &CStr {
         &self.name
     }