Fix some dead links in The Unstable Book

Author: ollie27

src/doc/unstable-book/src/language-features/advanced-slice-patterns.md

@@ -4,7 +4,7 @@ The tracking issue for this feature is: [#23121]
 
 [#23121]: https://github.com/rust-lang/rust/issues/23121
 
-See also [`slice_patterns`](slice-patterns.html).
+See also [`slice_patterns`](language-features/slice-patterns.html).
 
 ------------------------
 

src/doc/unstable-book/src/language-features/asm.md

@@ -190,4 +190,4 @@ constraints, etc.
 [llvm-docs]: http://llvm.org/docs/LangRef.html#inline-assembler-expressions
 
 If you need more power and don't mind losing some of the niceties of
-`asm!`, check out [global_asm](global_asm.html).
+`asm!`, check out [global_asm](language-features/global_asm.html).

src/doc/unstable-book/src/language-features/box-patterns.md

@@ -4,7 +4,7 @@ The tracking issue for this feature is: [#29641]
 
 [#29641]: https://github.com/rust-lang/rust/issues/29641
 
-See also [`box_syntax`](box-syntax.html)
+See also [`box_syntax`](language-features/box-syntax.html)
 
 ------------------------
 

src/doc/unstable-book/src/language-features/box-syntax.md

@@ -4,7 +4,7 @@ The tracking issue for this feature is: [#27779]
 
 [#27779]: https://github.com/rust-lang/rust/issues/27779
 
-See also [`box_patterns`](box-patterns.html)
+See also [`box_patterns`](language-features/box-patterns.html)
 
 ------------------------
 

src/doc/unstable-book/src/language-features/global_asm.md

@@ -74,5 +74,5 @@ usages and placed the larger, single usage in the crate root.
 
 If you don't need quite as much power and flexibility as
 `global_asm!` provides, and you don't mind restricting your inline
-assembly to `fn` bodies only, you might try the [asm](asm.html)
-feature instead.
+assembly to `fn` bodies only, you might try the
+[asm](language-features/asm.html) feature instead.

src/doc/unstable-book/src/language-features/plugin-registrar.md

@@ -8,6 +8,6 @@ This feature is part of "compiler plugins." It will often be used with the
 [`plugin`] and `rustc_private` features as well. For more details, see
 their docs.
 
-[`plugin`]: plugin.html
+[`plugin`]: language-features/plugin.html
 
 ------------------------

src/doc/unstable-book/src/language-features/plugin.md

@@ -8,7 +8,7 @@ The tracking issue for this feature is: [#29597]
 This feature is part of "compiler plugins." It will often be used with the
 [`plugin_registrar`] and `rustc_private` features.
 
-[`plugin_registrar`]: plugin-registrar.html
+[`plugin_registrar`]: language-features/plugin-registrar.html
 
 ------------------------
 

src/doc/unstable-book/src/language-features/slice-patterns.md

@@ -4,7 +4,8 @@ The tracking issue for this feature is: [#23121]
 
 [#23121]: https://github.com/rust-lang/rust/issues/23121
 
-See also [`advanced_slice_patterns`](advanced-slice-patterns.html).
+See also
+[`advanced_slice_patterns`](language-features/advanced-slice-patterns.html).
 
 ------------------------
 

src/doc/unstable-book/src/library-features/alloc-jemalloc.md

@@ -4,7 +4,7 @@ The tracking issue for this feature is: [#33082]
 
 [#33082]: https://github.com/rust-lang/rust/issues/33082
 
-See also [`alloc_system`](alloc-system.html).
+See also [`alloc_system`](library-features/alloc-system.html).
 
 ------------------------
 

src/doc/unstable-book/src/library-features/alloc-system.md

@@ -4,7 +4,7 @@ The tracking issue for this feature is: [#33082]
 
 [#33082]: https://github.com/rust-lang/rust/issues/33082
 
-See also [`alloc_jemalloc`](alloc-jemalloc.html).
+See also [`alloc_jemalloc`](library-features/alloc-jemalloc.html).
 
 ------------------------