create separate dep-nodes for predicates_of and explicit_predicates_of

src/librustc/dep_graph/dep_node.rs

@@ -500,6 +500,7 @@ define_dep_nodes!( <'tcx>
     [] TypeOfItem(DefId),
     [] GenericsOfItem(DefId),
     [] PredicatesOfItem(DefId),
+    [] ExplicitPredicatesOfItem(DefId),
     [] InferredOutlivesOf(DefId),
     [] InferredOutlivesCrate(CrateNum),
     [] SuperPredicatesOfItem(DefId),

src/librustc/ty/maps/mod.rs

@@ -102,7 +102,7 @@ define_maps! { <'tcx>
     /// associated generics and predicates.
     [] fn generics_of: GenericsOfItem(DefId) -> &'tcx ty::Generics,
     [] fn predicates_of: PredicatesOfItem(DefId) -> ty::GenericPredicates<'tcx>,
-    [] fn explicit_predicates_of: PredicatesOfItem(DefId) -> ty::GenericPredicates<'tcx>,
+    [] fn explicit_predicates_of: ExplicitPredicatesOfItem(DefId) -> ty::GenericPredicates<'tcx>,
 
     /// Maps from the def-id of a trait to the list of
     /// super-predicates. This is a subset of the full list of

src/librustc/ty/maps/plumbing.rs

@@ -1051,6 +1051,7 @@ pub fn force_from_dep_node<'a, 'gcx, 'lcx>(tcx: TyCtxt<'a, 'gcx, 'lcx>,
         DepKind::TypeOfItem => { force!(type_of, def_id!()); }
         DepKind::GenericsOfItem => { force!(generics_of, def_id!()); }
         DepKind::PredicatesOfItem => { force!(predicates_of, def_id!()); }
+        DepKind::ExplicitPredicatesOfItem => { force!(explicit_predicates_of, def_id!()); }
         DepKind::InferredOutlivesOf => { force!(inferred_outlives_of, def_id!()); }
         DepKind::InferredOutlivesCrate => { force!(inferred_outlives_crate, LOCAL_CRATE); }
         DepKind::SuperPredicatesOfItem => { force!(super_predicates_of, def_id!()); }

src/test/incremental/issue-51409.rs

@@ -0,0 +1,22 @@
+// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// revisions: rpass1
+
+// Regression test that `infer_outlives_predicates` can be
+// used with incremental without an ICE.
+
+#![feature(infer_outlives_requirements)]
+
+struct Foo<'a, T> {
+  x: &'a T
+}
+
+fn main() { }