edits to 'runtime'

Author: Kyle Strand

src/panic.md

@@ -30,7 +30,6 @@ been "cleaned up" just as if they had gone out of scope normally.
 > continue execution without recovering the panicked thread).
 
 ## Panic runtimes
-[top]: #panic-runtimes
 
 The actual behavior and implementation of `panic!` is controlled by the _panic
 runtime_.
@@ -43,7 +42,10 @@ When compiling code that is guaranteed to be linked to a non-recoverable panic
 runtime, the optimizer may assume that unwinding across Rust frames is
 impossible, which can result in both code-size and runtime speed improvements.
 
+See also ["The Rust runtime"][runtime].
+
 [destructors]: destructors.md
 [fn-catch-unwind]: ../std/panic/fn.catch_unwind.html
 [macro-panic]: ../std/macro.panic.html
 [thread-join]: ../std/thread/struct.JoinHandle.html#method.join
+[runtime]: runtime.md

src/runtime.md

@@ -47,8 +47,10 @@ fn panic(info: &PanicInfo) -> ! {
 
 The standard library provides an implementation of `panic_handler` that
 defaults to unwinding the stack but that can be [changed to abort the
-process][abort]. The standard library's panic behavior can be modified at
-runtime with the [set_hook] function.
+process][abort]. See also ["Panic runtimes"][panic-runtimes].
+
+The standard library's panic behavior can be modified at runtime with the
+[`set_hook` function][set_hook].
 
 ## The `global_allocator` attribute
 
@@ -80,6 +82,7 @@ display a console window on startup. It will run detached from any existing cons
 [abort]: ../book/ch09-01-unrecoverable-errors-with-panic.html
 [attribute]: attributes.md
 [crate types]: linkage.md
+[panic-runtimes]: panic.md#panic-runtimes
 [set_hook]: ../std/panic/fn.set_hook.html
 [static item]: items/static-items.md
 [subsystem]: https://msdn.microsoft.com/en-us/library/fcc1zstk.aspx