Auto merge of #73265 - mark-i-m:mv-std, r=Mark-Simulacrum,mark-i-m

mv std libs to library/

This is the first step in refactoring the directory layout of this repository, with further followup steps planned (but not done yet).

Background: currently, all crates are under src/, without nested src directories and with the unconventional `lib*` prefixes (e.g., `src/libcore/lib.rs`). This directory structures is not idiomatic and makes the `src/` directory rather overwhelming. To improve contributor experience and make things a bit more approachable, we are reorganizing the repo a bit.

In this PR, we move the standard libs (basically anything that is "runtime", as opposed to part of the compiler, build system, or one of the tools, etc). The new layout moves these libraries to a new `library/` directory in the root of the repo. Additionally, we remove the `lib*` prefixes and add nested `src/` directories.  The other crates/tools in this repo are not touched. So in summary:

```
library/<crate>/src/*.rs
src/<all the rest>     // unchanged
```

where `<crate>` is:
- core
- alloc
- std
- test
- proc_macro
- panic_abort
- panic_unwind
- profiler_builtins
- term
- unwind
- rtstartup
- backtrace
- rustc-std-workspace-*

There was a lot of discussion about this and a few rounds of compiler team approvals, FCPs, MCPs, and nominations. The original MCP is https://github.com/rust-lang/compiler-team/issues/298. The final approval of the compiler team was given here: https://github.com/rust-lang/rust/pull/73265#issuecomment-659498446.

The name `library` was chosen to complement a later move of the compiler crates to a `compiler/` directory. There was a lot of discussion around adding the nested `src/` directories. Note that this does increase the nesting depth (plausibly important for manual traversal of the tree, e.g., through GitHub's UI or `cd`), but this is deemed to be better as it fits the standard layout of Rust crates throughout most of the ecosystem, though there is some debate about how much this should apply to multi-crate projects. Overall, there seem to be more people in favor of nested `src/` than against.

After this PR, there are no dependencies out of the `library/` directory except on the `build_helper` (or crates.io crates).

1 files changed, 0 insertions, 127 deletions

diff --git a/src/libstd/os/haiku/fs.rs b/src/libstd/os/haiku/fs.rs
deleted file mode 100644
index 13a4a92ae90..00000000000
--- a/src/libstd/os/haiku/fs.rs
+++ /dev/null
@@ -1,127 +0,0 @@
-#![stable(feature = "metadata_ext", since = "1.1.0")]
-
-use crate::fs::Metadata;
-use crate::sys_common::AsInner;
-
-#[allow(deprecated)]
-use crate::os::haiku::raw;
-
-/// OS-specific extensions to [`fs::Metadata`].
-///
-/// [`fs::Metadata`]: ../../../../std/fs/struct.Metadata.html
-#[stable(feature = "metadata_ext", since = "1.1.0")]
-pub trait MetadataExt {
-    /// Gain a reference to the underlying `stat` structure which contains
-    /// the raw information returned by the OS.
-    ///
-    /// The contents of the returned `stat` are **not** consistent across
-    /// Unix platforms. The `os::unix::fs::MetadataExt` trait contains the
-    /// cross-Unix abstractions contained within the raw stat.
-    #[stable(feature = "metadata_ext", since = "1.1.0")]
-    #[rustc_deprecated(
-        since = "1.8.0",
-        reason = "deprecated in favor of the accessor \
-                  methods of this trait"
-    )]
-    #[allow(deprecated)]
-    fn as_raw_stat(&self) -> &raw::stat;
-
-    #[stable(feature = "metadata_ext2", since = "1.8.0")]
-    fn st_dev(&self) -> u64;
-    #[stable(feature = "metadata_ext2", since = "1.8.0")]
-    fn st_ino(&self) -> u64;
-    #[stable(feature = "metadata_ext2", since = "1.8.0")]
-    fn st_mode(&self) -> u32;
-    #[stable(feature = "metadata_ext2", since = "1.8.0")]
-    fn st_nlink(&self) -> u64;
-    #[stable(feature = "metadata_ext2", since = "1.8.0")]
-    fn st_uid(&self) -> u32;
-    #[stable(feature = "metadata_ext2", since = "1.8.0")]
-    fn st_gid(&self) -> u32;
-    #[stable(feature = "metadata_ext2", since = "1.8.0")]
-    fn st_rdev(&self) -> u64;
-    #[stable(feature = "metadata_ext2", since = "1.8.0")]
-    fn st_size(&self) -> u64;
-    #[stable(feature = "metadata_ext2", since = "1.8.0")]
-    fn st_atime(&self) -> i64;
-    #[stable(feature = "metadata_ext2", since = "1.8.0")]
-    fn st_atime_nsec(&self) -> i64;
-    #[stable(feature = "metadata_ext2", since = "1.8.0")]
-    fn st_mtime(&self) -> i64;
-    #[stable(feature = "metadata_ext2", since = "1.8.0")]
-    fn st_mtime_nsec(&self) -> i64;
-    #[stable(feature = "metadata_ext2", since = "1.8.0")]
-    fn st_ctime(&self) -> i64;
-    #[stable(feature = "metadata_ext2", since = "1.8.0")]
-    fn st_ctime_nsec(&self) -> i64;
-    #[stable(feature = "metadata_ext2", since = "1.8.0")]
-    fn st_crtime(&self) -> i64;
-    #[stable(feature = "metadata_ext2", since = "1.8.0")]
-    fn st_crtime_nsec(&self) -> i64;
-    #[stable(feature = "metadata_ext2", since = "1.8.0")]
-    fn st_blksize(&self) -> u64;
-    #[stable(feature = "metadata_ext2", since = "1.8.0")]
-    fn st_blocks(&self) -> u64;
-}
-
-#[stable(feature = "metadata_ext", since = "1.1.0")]
-impl MetadataExt for Metadata {
-    #[allow(deprecated)]
-    fn as_raw_stat(&self) -> &raw::stat {
-        unsafe { &*(self.as_inner().as_inner() as *const libc::stat as *const raw::stat) }
-    }
-    fn st_dev(&self) -> u64 {
-        self.as_inner().as_inner().st_dev as u64
-    }
-    fn st_ino(&self) -> u64 {
-        self.as_inner().as_inner().st_ino as u64
-    }
-    fn st_mode(&self) -> u32 {
-        self.as_inner().as_inner().st_mode as u32
-    }
-    fn st_nlink(&self) -> u64 {
-        self.as_inner().as_inner().st_nlink as u64
-    }
-    fn st_uid(&self) -> u32 {
-        self.as_inner().as_inner().st_uid as u32
-    }
-    fn st_gid(&self) -> u32 {
-        self.as_inner().as_inner().st_gid as u32
-    }
-    fn st_rdev(&self) -> u64 {
-        self.as_inner().as_inner().st_rdev as u64
-    }
-    fn st_size(&self) -> u64 {
-        self.as_inner().as_inner().st_size as u64
-    }
-    fn st_atime(&self) -> i64 {
-        self.as_inner().as_inner().st_atime as i64
-    }
-    fn st_atime_nsec(&self) -> i64 {
-        self.as_inner().as_inner().st_atime_nsec as i64
-    }
-    fn st_mtime(&self) -> i64 {
-        self.as_inner().as_inner().st_mtime as i64
-    }
-    fn st_mtime_nsec(&self) -> i64 {
-        self.as_inner().as_inner().st_mtime_nsec as i64
-    }
-    fn st_ctime(&self) -> i64 {
-        self.as_inner().as_inner().st_ctime as i64
-    }
-    fn st_ctime_nsec(&self) -> i64 {
-        self.as_inner().as_inner().st_ctime_nsec as i64
-    }
-    fn st_crtime(&self) -> i64 {
-        self.as_inner().as_inner().st_crtime as i64
-    }
-    fn st_crtime_nsec(&self) -> i64 {
-        self.as_inner().as_inner().st_crtime_nsec as i64
-    }
-    fn st_blksize(&self) -> u64 {
-        self.as_inner().as_inner().st_blksize as u64
-    }
-    fn st_blocks(&self) -> u64 {
-        self.as_inner().as_inner().st_blocks as u64
-    }
-}