Rollup merge of rust-lang#57259 - king6cong:master, r=alexcrichton

Update reference of rlibc crate to compiler-builtins crate

None

src/libcore/lib.rs

@@ -24,7 +24,7 @@
 //! often generated by LLVM. Additionally, this library can make explicit
 //! calls to these functions. Their signatures are the same as found in C.
 //! These functions are often provided by the system libc, but can also be
-//! provided by the [rlibc crate](https://crates.io/crates/rlibc).
+//! provided by the [compiler-builtins crate](https://crates.io/crates/compiler_builtins).
 //!
 //! * `rust_begin_panic` - This function takes four arguments, a
 //! `fmt::Arguments`, a `&'static str`, and two `u32`'s. These four arguments