Try to fix build

Author: lnicola

src/tools/rust-analyzer/crates/hir-ty/src/next_solver/consts.rs

@@ -36,6 +36,11 @@ impl<'db> Const<'db> {
             internee: kind,
             flags: flags.flags,
             outer_exclusive_binder: flags.outer_exclusive_binder,
+            #[cfg(feature = "in-rust-tree")]
+            stable_hash: {
+                // SAFETY: These have the same layout.
+                unsafe { std::mem::transmute(crate::next_solver::util::Fingerprint::ZERO) }
+            },
         };
         Const::new_(interner.db(), InternedWrapperNoDebug(cached))
     }

src/tools/rust-analyzer/crates/hir-ty/src/next_solver/inspect.rs

@@ -1,4 +1,4 @@
-pub use ra_ap_rustc_next_trait_solver::solve::inspect::*;
+pub use rustc_next_trait_solver::solve::inspect::*;
 
 use rustc_ast_ir::try_visit;
 use rustc_next_trait_solver::{

src/tools/rust-analyzer/crates/hir-ty/src/next_solver/predicate.rs

@@ -227,6 +227,11 @@ impl<'db> Predicate<'db> {
             internee: kind,
             flags: flags.flags,
             outer_exclusive_binder: flags.outer_exclusive_binder,
+            #[cfg(feature = "in-rust-tree")]
+            stable_hash: {
+                // SAFETY: These have the same layout.
+                unsafe { std::mem::transmute(crate::next_solver::util::Fingerprint::ZERO) }
+            },
         };
         Predicate::new_(interner.db(), InternedWrapperNoDebug(cached))
     }

src/tools/rust-analyzer/crates/hir-ty/src/next_solver/ty.rs

@@ -60,6 +60,11 @@ impl<'db> Ty<'db> {
             internee: kind,
             flags: flags.flags,
             outer_exclusive_binder: flags.outer_exclusive_binder,
+            #[cfg(feature = "in-rust-tree")]
+            stable_hash: {
+                // SAFETY: These have the same layout.
+                unsafe { std::mem::transmute(crate::next_solver::util::Fingerprint::ZERO) }
+            },
         };
         Ty::new_(interner.db(), InternedWrapperNoDebug(cached))
     }

src/tools/rust-analyzer/crates/hir-ty/src/next_solver/util.rs

@@ -1062,3 +1062,11 @@ pub fn sizedness_fast_path<'db>(
 
     false
 }
+
+/// This is a copy of [`rustc_data_structures::fingerprint::Fingerprint`], which we can't construct on stable.
+#[repr(C)]
+pub struct Fingerprint(u64, u64);
+
+impl Fingerprint {
+    pub const ZERO: Fingerprint = Fingerprint(0, 0);
+}