Replace rust-rfcs with rust-lang

Author: JohnTitor

promotion.md

@@ -65,7 +65,7 @@ Currently, non-`Copy` array initialization is treated as an implicit context.
 
 The distinction between these two determines whether calls to arbitrary `const
 fn`s (those without `#[rustc_promotable]`) are promotable (see below). See
-[rust-rfcs/const-eval#19](https://github.com/rust-rfcs/const-eval/issues/19)
+[rust-lang/const-eval#19](https://github.com/rust-lang/const-eval/issues/19)
 for a thorough discussion of this. At present, this is the only difference
 between implicit and explicit contexts. The requirements for promotion in an
 implicit context are a superset of the ones in an explicit context.

rfcs/const-generic-const-fn-bounds.md

@@ -298,7 +298,7 @@ type theoretical perspective started out with a much purer scheme, but, when exp
 constraints required, evolved to essentially the same scheme as this RFC. We thus feel confident
 that this RFC is the minimal viable scheme for having bounds on generic parameters of const
 functions. The discussion and evolution of the type theoretical scheme can be found
-[here](https://github.com/rust-rfcs/const-eval/pull/8#issuecomment-452396020) and is only 12 posts
+[here](https://github.com/rust-lang/const-eval/pull/8#issuecomment-452396020) and is only 12 posts
 and a linked three page document long. It is left as an exercise to the reader to read the
 discussion themselves.
 A summary of the result of the discussion can be found at the bottom of [this blog post](https://varkor.github.io/blog/2019/01/11/const-types-traits-and-implementations-in-Rust.html)