Rename upvars query to upvars_mentioned

Author: JohnTitor

src/closure.md

@@ -115,9 +115,10 @@ Let's start with defining a term that we will be using quite a bit in the rest o
 *upvar*. An **upvar** is a variable that is local to the function where the closure is defined. So,
 in the above examples, **x** will be an upvar to the closure. They are also sometimes referred to as
 the *free variables* meaning they are not bound to the context of the closure.
-[`src/librustc_middle/ty/query/mod.rs`][upvars] defines a query called *upvars* for this purpose.
+[`src/librustc_middle/ty/query/mod.rs`][upvars] defines a query called *upvars_mentioned*
+for this purpose.
 
-[upvars]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/query/queries/struct.upvars.html
+[upvars]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/ty/query/queries/struct.upvars_mentioned.html
 
 Other than lazy invocation, one other thing that the distinguishes a closure from a
 normal function is that it can use the upvars. It borrows these upvars from its surrounding