E0735 -> E0739

Prevents number collision with another approved PR.

src/librustc/error_codes.rs

@@ -2145,5 +2145,5 @@ See [RFC 2091] for details on this and other limitations.
     E0726, // non-explicit (not `'_`) elided lifetime in unsupported position
     E0727, // `async` generators are not yet supported
     E0728, // `await` must be in an `async` function or block
-    E0735, // invalid track_caller application/syntax
+    E0739, // invalid track_caller application/syntax
 }

src/librustc/hir/check_attr.rs

@@ -143,7 +143,7 @@ impl CheckAttrVisitor<'tcx> {
             struct_span_err!(
                 self.tcx.sess,
                 attr.span,
-                E0735,
+                E0739,
                 "attribute should be applied to function"
             )
             .span_label(item.span, "not a function")

src/test/ui/rfc-2091-track-caller/only-for-fns.stderr

@@ -6,7 +6,7 @@ LL | #![feature(track_caller)]
    |
    = note: `#[warn(incomplete_features)]` on by default
 
-error[E0735]: attribute should be applied to function
+error[E0739]: attribute should be applied to function
   --> $DIR/only-for-fns.rs:3:1
    |
 LL | #[track_caller]