Use HashStable_Generic in rustc_type_ir

A lot of the types in this crate implemented HashStable directly to
avoid circular dependencies. One way around that is to use
HashStable_Generic. We adopt that here to avoid a lot of boilerplate.

This doesn't update all the types, because some would require
`I: Interner + HashStable`.

2 files changed, 3 insertions, 0 deletions

diff --git a/compiler/rustc_query_system/Cargo.toml b/compiler/rustc_query_system/Cargo.toml
index bafc6b0a082..d7599a56c0b 100644
--- a/compiler/rustc_query_system/Cargo.toml
+++ b/compiler/rustc_query_system/Cargo.toml
@@ -21,6 +21,7 @@ rustc_serialize = { path = "../rustc_serialize" }
 rustc_session = { path = "../rustc_session" }
 rustc_span = { path = "../rustc_span" }
 rustc_target = { path = "../rustc_target" }
+rustc_type_ir = { path = "../rustc_type_ir" }
 smallvec = { version = "1.8.1", features = ["union", "may_dangle"] }
 thin-vec = "0.2.8"
 tracing = "0.1"
diff --git a/compiler/rustc_query_system/src/ich/impls_syntax.rs b/compiler/rustc_query_system/src/ich/impls_syntax.rs
index d7732cb1825..0bc811eb044 100644
--- a/compiler/rustc_query_system/src/ich/impls_syntax.rs
+++ b/compiler/rustc_query_system/src/ich/impls_syntax.rs
@@ -148,3 +148,5 @@ impl<'tcx> HashStable<StableHashingContext<'tcx>> for rustc_feature::Features {
         });
     }
 }
+
+impl<'ctx> rustc_type_ir::HashStableContext for StableHashingContext<'ctx> {}