use drop-temps { .. } pseudo-notation

DropTemps(...) looks like a function, this looks like wacko special stuff

Author: nikomatsakis

src/librustc/hir/lowering/expr.rs

@@ -351,7 +351,7 @@ impl LoweringContext<'_> {
                 //
                 // ```
                 // 'label: loop {
-                //     match DropTemps($cond) {
+                //     match drop-temps { $cond } {
                 //         true => $body,
                 //         _ => break,
                 //     }