Rollup merge of #56808 - jrvidal:broken-links, r=kennytm
Fixes broken links
Just a few broken links.
Not sure what to do about this one: https://github.com/rust-lang/rust/blame/master/src/doc/unstable-book/src/language-features/plugin.md#L135 (regex macros were removed a while ago in https://github.com/rust-lang/regex/commit/037595438947eeb4c63a0185065b0143a7f2ac2c).
diff --git a/src/doc/rustc/src/targets/built-in.md b/src/doc/rustc/src/targets/built-in.md
index 8620346..2e94ebe 100644
--- a/src/doc/rustc/src/targets/built-in.md
+++ b/src/doc/rustc/src/targets/built-in.md
@@ -6,5 +6,5 @@
To see the list of built-in targets, you can run `rustc --print target-list`,
or look at [the API
-docs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_back/target/#modules).
+docs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_target/spec/index.html#modules).
Each module there defines a builder for a particular target.
\ No newline at end of file
diff --git a/src/doc/rustc/src/targets/index.md b/src/doc/rustc/src/targets/index.md
index 07e3a79..3d63d07 100644
--- a/src/doc/rustc/src/targets/index.md
+++ b/src/doc/rustc/src/targets/index.md
@@ -4,7 +4,7 @@
architecture. The list of *targets* are the possible architectures that you can build for.
To see all the options that you can set with a target, see the docs
-[here](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_back/target/struct.Target.html).
+[here](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_target/spec/struct.Target.html).
To compile to a particular target, use the `--target` flag:
diff --git a/src/doc/unstable-book/src/language-features/unsized-locals.md b/src/doc/unstable-book/src/language-features/unsized-locals.md
index 1165ab9..edc039f 100644
--- a/src/doc/unstable-book/src/language-features/unsized-locals.md
+++ b/src/doc/unstable-book/src/language-features/unsized-locals.md
@@ -8,7 +8,7 @@
This implements [RFC1909]. When turned on, you can have unsized arguments and locals:
-[RFC1909]: https://github.com/rust-lang/rfcs/blob/master/text/1909-coercions.md
+[RFC1909]: https://github.com/rust-lang/rfcs/blob/master/text/1909-unsized-rvalues.md
```rust
#![feature(unsized_locals)]
