Auto merge of #138595 - jhpratt:rollup-09pvfzu, r=jhpratt

Rollup of 9 pull requests

Successful merges:

 - #136355 (Add `*_value` methods to proc_macro lib)
 - #137621 (Add std support to cygwin target)
 - #137793 (Stablize anonymous pipe)
 - #138341 (std: Mention clone-on-write mutation in Arc<T>)
 - #138517 (Improve upvar analysis for deref of child capture)
 - #138584 (Update Rust Foundation links in Readme)
 - #138586 (Document `#![register_tool]`)
 - #138590 (Flatten and simplify some control flow 🫓)
 - #138592 (update change entry for #137147)

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 7 insertions, 0 deletions

diff --git a/library/std/src/sys/random/getrandom.rs b/library/std/src/sys/random/getrandom.rs
new file mode 100644
index 00000000000..0be2eae20a7
--- /dev/null
+++ b/library/std/src/sys/random/getrandom.rs
@@ -0,0 +1,7 @@
+pub fn fill_bytes(mut bytes: &mut [u8]) {
+    while !bytes.is_empty() {
+        let r = unsafe { libc::getrandom(bytes.as_mut_ptr().cast(), bytes.len(), 0) };
+        assert_ne!(r, -1, "failed to generate random data");
+        bytes = &mut bytes[r as usize..];
+    }
+}